It’s easy enough to find new tires for an old muscle car.
Just not performance tires.
Not for the stock wheels, that is.
I own a ’76 Trans-Am. Like most cars of its era (mid-late ’60s through the early ’80s), it came from the factory with 15×7 wheels. And therein lies the rub. It’s been decades since a 15×7 wheel was considered a performance wheel. Most modern performance cars have at least 16×8 wheels – and that’s getting small, by the latest standards (the ’14 Camaro Z28 comes factory equipped with 19-inch wheels).
Most modern performance tires are not sold in sizes that will fit a 15×7 wheel – and haven’t been, for years.
You can get reproductions of the original “back in the day” tires – including, for instance, the Goodyear Polysteel Radials that my car had when it left the Norwood, Ohio assembly line back in the early spring of 1976. But while “correct” reproduction tires are what you want for a serious restoration, they’re not much better (and may even be not as good as) a modern all-season radial like the BF Goodrich Radial T/A, as far as lateral grip, traction and high-speed capability.
The Radial T/A is a common sight on older muscle cars because it’s one of the very few new tires you can get in several sizes that will fit a 15×7 wheel and which is sold in larger-than-stock sizes such as 245/60-15, which is what I have on the TA in lieu of the factory 225/70-15s.
Yes, they used to factory equip RWD V-8 muscle cars with 70-series radials.
It’s one of the reasons why cars from that era were so loosey-goosey in the tail. The wider footprint of a larger tire like the 245/60 helps a lot. In the curves, too. But there’s only so much you can do with a tire like the Radial T/A, which looks sporty because of its raised white lettering – but which is basically just an ordinary passenger car radial. It is not rated for high-speed use and its compound/tread aren’t especially aggressive.
Of course, you could always replace your classic muscle car’s factory 15×7 wheels with a set of larger wheels in order to take advantage of the handling/braking/traction advantages of modern performance tires – but doing so is not an option for people like me who want to retain the original look and stance of their classic cars. The younger crowd may not comprehend this desire – wheels being wheels these days. One chromed look-alike after the next. But back in the day, factory wheels were a major styling element that helped define a given car – not just its model but also its brand.
My car, for example, came through with what Pontiac called “Honeycomb” wheels. These were unique to Pontiacs of the period (’76 was actually the last year you could order them new from the factory). Similarly, the various division-specific Rally (I and II) wheels put on Chevys, Buicks and Oldsmobiles. There was an incredible variety – in every way but the size.
Most were 15×7.
Now, Year One (among others) does offer a modernized (17×9) version of the Pontiac Honeycomb – as well as updated/larger versions of other classic-era muscle car wheels such as the Mopar Rallye wheel (see here for the list) but a lot of people – me included – don’t think they look right. Wheels this tall (as well as wide) and the short-sidewall tires that mount on them may also not work right – on a car with an otherwise stock suspension. (The Bandit Trans-Am that Year One built to show off the modern Honeycombs was heavily modified, including a 4-link rear suspension and adjustable coil-over shocks all around.)
But, it’s not completely hopeless.
I was rummaging around the Internet the other day and discovered that Goodyear is re-issuing the famous Gatorback – and in at least one size that will fit a 15×7 wheel: 225/60VR-15. The Gatorback was standard equipment on early-mid-1980s rippers like the Mustang GT and, of course, the 1984 Corvette. It is a serious tire – with a 150 MPH (VR) speed rating.
Though it’s just the one size (for now), the 225/60VR-15 Gatorback is actually a larger tire than the factory 225/70-15 that my car came with originally. They’re not cheap, of course. The supplier I found (see here) prices them at $290 per tire, not including shipping. This is about twice the cost of a raised white letter Radial T/A, but it’s in line with the cost of other modern high-performance tires. Remember: Though sporty-looking, the Radial T/A is not a sport tire. It’s a standard all-season tire – and not high-speed rated. It’s fine for just knocking around on – and it’s just the ticket (being cheap) to shred doing 50-yard burnouts when the mood strikes. But for serious road work – especially high-speed road work – a VR-speed rated ultra-performance tire like the Gatorback is what you want. 
Unfortunately, for now at least, you can only get it in that one size – if you want it for a 15-inch rim.
It’s a start, though – and it’s definitely better than nothing (and better for performance driving than the good-looking but out-of-date Radial T/A).
Perhaps if enough people express interest, Goodyear – or BF Goodrich/Uniroyal or some other tire company – will decide to offer more in the way of serious rubber for those of us who are serious about keeping the stock rims on our rides.
Throw it in the Woods?Â
I can’t stand the Chip Foose wheels of today. Especially on classic cars. The wheel radius is way out of proportion to the wheel well curve and it makes the car look like a gigantic Matchbox car.
David, yep. You have a slammed ’67 Impala with an exotic/almost old style looking wheel that would fit a Peterbilt or looks that way. It’s gonna be at least a 20″ and Matchbox is accurate in the way it makes the entire car look. I watched Chip enough where I knew what his designs would look like and didn’t really like them at all. How swoopy can you make those old cars look and retain any of what made them look good? Wish I could find my old notebook of drawings of what Pete’s and the like would look like if I could build them. They’re close to what has finally been produced except not nearly so classy looking. I have bunches of pickup sized drawings I made off big rig tractors too. Now that’s what they should look like now instead of those big nosed, squared off things they pass for pickups now. I contend my ’93 Chevy is the best looking factory pickup ever made, bar none. Except for the old Stude’s.
And a 46 Ford pickup.
Ditto, David.
I cringe every time I see a ’60s or ’70s muscle car ruined in this way.
My teeth also hurt whenever I walk up to a Pontiac or Buick or Olds muscle car… and see a crate Chevy small block under the hood.
Nothing wrong with the SBC. It is a brilliant engine, in fact. But it is not a Pontiac engine – or a Buick engine or an Olds engine – and putting a SBC in place of the original Pontiac or Buick or Olds engine ruins the car. It now sounds, runs and drives like any other Chevy.
eric, do you know of a site where I could find specific information about my El Camino? I know how many SS’s were made in ’77 but can’t find out how many were trailer tow packages and all the mechanical parts are different including wheel and tire size.
Hi Eight,
Wish I could help, but other than the general stuff you probably already know about…. I’m a Pontiac weirdo, after all!
The problem is the difficulty working with the other engines if one wants modern fuel injected power. Because GM killed all non-caddy division V8s they didn’t make it past the early 1980s. Choices are limited. Some of the engines never had any performance parts made for them. The ’82 Olds that sits in my garage has a 307V8, a good decent engine with a computer controlled quadrajet. However there is nothing that can be done to it really except rebuild it to stock. That’s about it. There’s the Holley TB injection kit but last I looked it was very costly.
To get modern reliable horsepower the easiest thing to do is drop in a modern chevy V8 and trans. It’s also probably the cheapest.
But that doesn’t make it right. I believe in retaining the true division engine, but there’s just limits to what can be done that way. Even if turning it into a giant engineering development project.
BrentP, good? decent? must be one of a kind. I need a quirt to drive one. Instead of a 403 transplant, stick a Poontang 400 with an Olds air cleaner in it and nobody will know if you cover up the ram air intake. Gitty up go!! and no need to whip it…..but what about those brakes? Put some Edelbrock Performer IAS shocks on it to avoid the roller coaster thing and a 700 R4 to get some mileage. Go by the cops @120 and watch them beat on their radar gun.
It’s a big car… doesn’t need to be fast. As far as the typical ‘put a 455 in it’ advice…. might as well just put in a modern SBC.
Hey Eight,
I’d know!
You’d have to weld on the Oldsmobile V-8’s really obvious oil filler tube (located at the front of the engine) as well as craft a set of Olds-esque valve covers to make the 400 Pontiac look (to anyone who knows the difference) like an Olds!
PS: (And I know you know this, but for the peanut gallery):
The 403 Olds V-8 is by no means dog. It has a rep for being one because in stock trim, it was never much to write home about. But it is easily hopped-up and can be made (like any Olds V-8) into a potent performer. I have nothing against the 403 at all. I just don’t like to see ’em in Pontiacs, is all!
eric, I have personal experience with Olds 403’s that will haul the mail, definitely respond to nothing more than a cam change. You could probably go a size bigger secondary needles on the Q-jet and get a bit more power also. Most engines do respond well to a cam change though. I was just being facetious since the Pontiac 400 ram air engine is a real performer and a plain old 1968 year model Ram Air cam would warm any of them up. I suspect there are some really great cams for them these days. No doubt all the gear heads here know this but don’t feel like you have to buy a certain model cam when making a change. Good cam makers will grind custom cams for not much over what an off the shelf cam costs so you can tune it to the head/intake combo you have as well as the weight/gearing of the vehicle. Often cams like this are hard to detect they’re ground so well.
Yup!
Years ago, a friend owned a ’78 Trans-Am with the 403 and an automatic. This version of the Trans-Am was particularly hobbled (in terms of acceleration) by its “highway” rear axle ratio – something like 2.41 if I recall correctly. We swapped in a 3:23 rear end from a 400, 4-speed car and that alone really woke the ’78 up.
We put a shift kit in the transmission, pulled the stock Y-pipe single exhaust with the hugely restrictive “pellet” style GM cat, replacing it with duals and glasspacks. That plus some fiddling with the timing and carb jets resulted in a 403 TA that felt (and probably was) as quick or even quicker than a stock “T/A 6.6” 400-equipped TA.
We never put a cam in, but I expect that would have made a huge difference.
Ditto heads/higher CR.
Stock, the mid-late ’70s Olds (and Pontiac) V-8s had (by modern standards) ridiculously low compression. My TA’s 455, for example, had a stock CR of 7.6:1 – no shit.
Seriously.
Hi Brent,
Isn’t it true that most of the TBI-type systems will pretty readily mount to any conventional “wet” 4 BBL (or even 2BBL) intake? Are the Chevy versions of the Edelbrock and Holley systems significantly less costly than the ones for say Pontiac or Olds V-8s? I thought they were universal fit?
I don’t see the cost-benefit of these systems, regardless. I’m sure you’ll agree with me that a properly set-up Quadrajet will give you very close to FI driveability (cold start, throttle response, etc.) for much less outlay in terms of the initial investment as well as down-the-road costs. But, regardless, it’s not that big a deal, money-wise to “TBI” a classic V-8.
Now, if you want port fuel injection, you’re talking big bucks – obviously.
On that 307: Isn’t it just a smaller bore standard Olds V-8, with major parts such as heads, camshaft and intake interchangeable with the 350/403 Olds? (I can’t recall for sure, but my memory is that the Olds 307 is not like the Pontiac 301, which shares no major parts with the traditional Pontiac V-8 (326/350/400; 421/428/455).
eric, the 307 is the same engine as the 350/403. TBI’ing it can be done via the whole intake/TBI from other engines in this line, a 75-81 Seville has that engine with TBI so it’s mainly a matter of matching electrical connections, kick down cable, throttle cable. You’ll lose 40 lbs. of intake this way, a real good thing. Don’t sweat the TBI source, just about any GM will work, 4.3L, 350, 305. For ease though, I’d rob an intake from a Seville, enlarge the fuel holes and use a Chev. TBI. GM parts interchange over a huge variety of engines, the beauty of GM’s. You’ll want to re-curve the distributor or get one from the Seville probably. It sounds a lot worse than doing it though and you’ll be trouble free with a much better engine when you’re done. Hint: I’d chunk the 307 and do all this to the 403 since it has a great deal more potential and very little difference in fuel mileage. 403’s have a short stroke, big bore combo so they rev freely, just not over 6,000 rpm if you like things all together. They have a bigger bore than a BBC so there you go. 403’s are known for long life opposed to the 307 which isn’t so long although not a bad engine. 350 heads will increase the CR from the stock 8:1 on a 403 to somewhere around 9.0:1 depending on head gasket/material removed by decking the head. Stick it together and run it, do some smoky burnouts with it, avoid machine work if the heads are known good. ’72 7a’s are the ticket but 68-72 are fine.
The computer controlled quadrajet works fine when it works, the problem being it is still a carb and still requires attention to stay that way.
Adapting TB systems from other cars is doable but it is an engineering project. That’s not expensive. The aftermarket ones assemble just fine, just cost a lot. It’s been a long time since I looked at stuff and there are conversion kits now for injectors in the manifold runners as well. Maybe they are cheaper now… they were thousands of dollars when I looked last. Brief search, cheaper, but still a grand or more.
I no longer remember the details on the 307. Some things are compatible some aren’t. Basically my point is that some of these engines are just easier to replace wholesale if one wants something more than stock.
I’m a big booster of the Q-Jet (as you know). Once set properly, I don’t find it needs much attention beyond occasional cleaning. Disassembly (once you’re familiar with them) is a snap. I’m by no means in the same league as Cliff Ruggles, but I swear on a stack of Honeycomb rims I can tear down, clean and (properly) put back together a Q-Jet in less than an hour. Assuming the base plate (and other castings) aren’t warped from over-tightening, these carbs can last for a lifetime.
I’m pretty sure you can use most 350/403 heads – and intakes – on the 307. It’s not a bad little engine at all (in the early-mid ’80s Hurst Olds it made a respectable 180 hp) and I’d keep it just because of its unusualness… these days.
I bet a mild cam, headers and some tuning would get 250-275 honest RWHP out of one and still be nearly as streetable as the stock 307!
I know they are good carbs, they are still carbs however and require attention that FI doesn’t. The time taken to disassemble clean, reassemble a carb is time lost from something else.
People also switch things over because they run into barriers with these engines that GM basically discarded. I’m not saying its the right thing to do, or there aren’t other options, they are just more difficult, time consuming, and/or more costly. Especially for the smaller displacements versions that didn’t get performance attention back in the day.
All true.
In the case of my Pontiac V-8s, pretty much any given component is going to cost you more (and is usually harder to find) than the same item for a SBC.
On the other hand, there is something appealing (to me, at least) about a different type of engine. SBCs are, literally, everywhere. A Pontiac 455? Not so much!
Plus, they have their own merits vis-a-vis the SBC. My Pontiac, for instance, produces tremendous torque at comparatively low RPMs (Buick V-8s are even better in this respect). Also, you can use factory cast-iron headers (manifolds, really – but high-performance, nonetheless). These are hard to find for SBCs, forcing the use of headers, which leak and are loud.
BrentP, I’m a Q-jet man myself. Grab a collection of primary and secondary needle sets and you can fine tune one to any engine…..or just stick on a TBI and forget it. Put a performance air cleaner on TBI and waaaaaaaaaaaaaaaaaaaaaaa
eric, I once had a set of cast iron high performance SBC manifolds that were rare, don’t know what engine they originated on. They were made like something tuned with 2 1/2″ collectors for that size exhaust pipes, every bit as good as tube headers and NEVER Leaked.
Morning, Eight!
Yup – IIRC, Chevy made some back in the late ’50s or early ’60s, possibly for the Corvette 327?
I like these iron “manifold headers” a lot, for all the reasons mentioned: They fit better, they are quieter, they don’t leak and they last forever. The Pontiac Ram Air manifolds – available for both the D-port and the Round Port heads – is an excellent alternative to tube headers. The main downside to them is their weight. They’re each close to 25 pounds, IIRC.
eric, good morning. I think those SBC manifolds were for ‘Vettes, like a rare 375hp version right before the 350 debuted. A couple friends has those Ram Air Firebirds with that very manifold, running sumbitches they were. In some ways I liked them better than the TA’s. The ’69 or ’70 Ram Air 111 or something like that was a real screamer. A girl a couple years older than me had one I used to wash for her. It would always be choking and running like hell before I washed it and then miraculously screaming like a top afterward. Funny that ha ha. She never mentioned it. I bet she noticed though.
eric,
I have run a set of dunlop direzza’s and falken azenis in 205-50R15 on my mr2, i think they are super sticky but finding anything above a 205 is going to be pretty tough in 15″. i actually prefer the slightly taller sidewall. the taller sidewall with the midengine setup gives me more warning before the rear snaps around.
not sure why these aren’t an option for your 15X7’s but these 2 are great and for abotu $100/tire it doesn’t break the bank. the direzzas are a better summer/road tire in my opinion.
Brent, I don’t remember the name of the company but somebody used to make wheels for whatever car you wanted, maybe several wheel companies did. You gave them the specs and they’d build that wheel. Often on cars like yours and others, F-Body cars being one I can think of, they will take wider wheels but the offset is the difference. I do recall you could get wheels for cars like eric’s that were 1.5″ wider or maybe even wider but they had specific offsets inside and outside. My SS El Camino wheels are completely different from anything else GM made because they are half and inch wider at 7.5″ and the offset is stuck back under the car with a really narrow beauty ring that will fit no other wheel. I bought it slightly used and a guy had the spare on the ground cause he’d bent the rt. frnt. on a dumpster. I had a friend who worked at a GM dealership and when I ordered that wheel, the parts guy said Hm, that’s an odd duck. It surely was and just came with some primer on it. Cost me more than a new custom wheel too.
I know wheels can be made special. fender lips can be rolled under, etc and so on…. Interesting factoid.. my ’12 Mustang the lips are rolled in from the factory. Anyway I want to use the alloys I spent so much time taking from junk to mirror polish. Hunting down mav center caps on ebay…. all that time drilling broken center cap screws out and retapping and breaking taps… all to have the wheels I wanted when I was 16. I’ll buy special tires first! 🙂
I was taught to massage fenders out with a rubber mallet, easy to get 1/2-1″ on some cars but 1/2″ on anything.
There are better ways these days to get roll in the lip. Eastwood sells a tool for it. ( http://www.eastwood.com/ew-fender-roller-w-instruction.html ) I have never used it so I can’t say how good it works. Eastwood to me has been hit or miss with other stuff.
Brent, that looks like a good tool to do that one thing and esp. on new cars. Older cars and their rear fenders often have room to move the entire edge out. That tool might be good for that and might be good for just part of that. If I wanted to perform that mod I’d like to try it though. It would sure be a good start before you got out various pieces of wood, hammers and mallets.
Well I have found pickings have gotten small since I bought new tires for my mav a decade ago. 14×6 wheels. I have a set of factory alloys which I put far too much money and time into to make pretty. set of five. I paid way too much for the fifth one, but I had to have one of the first four welded and I just don’t trust it even though they did a decent job they had to remove some material to get a good weld. I can live with a regular all season tire on that car… even after I mess with the engine it won’t have all that much power.
Here’s the kicker, I have SN95 mustang wheels and they have the right bolt pattern but they hit the leaf springs in back and can’t be installed, on the front they rub on the suspension top arm or close to it. They’ll mount but I wouldn’t drive the car like that. I saw a comet at a car show that much wider than stock rear wheels and I took a look to see how they got them on…. the leaf springs were notched. Notches cut in them….
Brent,
“the leaf springs were notched. Notches cut in them….”
Remember Higgins from Magnum, PI?
Oh… my god!
The previous owner had done something else besides notching them which I can’t remember at the moment, but that wasn’t enough so the springs were notched on top of it.
But that was my unsaid reaction as well…. notching and cutting isn’t good for springs. Even on TV they show people cutting coil springs down…. totally wrong way to lower a car. I even saw torching a spring, annealing it, to do it on one show. It’s scary knowing that they then sell those cars and people at home will be tempted to the same crap.
Springs are never right after they’ve been changed. Cutting off the ends of coils destroys the proper end condition too. Shops will make fresh custom leaf and coil springs if there aren’t suitable aftermarket ones available. It’s really a stupid way to save money IMO.
Brent, I bought new coils for the Elco, was going to use an automatic saw and take an inch off. Still have those springs, brand new with GM tags. If it goes down an inch it’ll be because it has an air bag system more than likely. I don’t like to go up or down very much due to geometry changes. I’ve always wondered if those Tahoes and Yukons(just to name 2 big sellers)with 20″ wheels work well in the long run since you can get the same vehicle with 16″. Of course if you live in Odessa, 20″ is junk you need to resell after you get your 24’s on. It’s like Odessa is in a vacuum and everybody does the same thing. Every private vehicle it seems has some identifying marker. I guess that’s so when the cops don’t catch you doing something they see you doing they’ll still know who it was. Cop All I could see was a dark blue two door vs Cop All I could see was a dark blue two door but when he got on by I saw it was David de Silva. Other cop, How do you know that? Cop, it was on the rear window. Good move.
Yep, suspension geometry changes are due to the amount of lowering. The cutting or annealing however changes how the spring works, how it responds to load, how it seats, etc. It’s messing with the way the spring carries load and how it reacts dynamically. These changes can be undesirable and even unsafe.
A properly made lowering spring will change the rate of the spring and the height to keep the suspension working properly. Not bottoming out, etc and so on. The end conditions, close coils, ground, reduced or increased diameter, etc is also maintained.
eric, I guess I’m lucky in that my ’77 El Camino wheels fit only one model, the trailer towing version. They’re 7.5″X15 and hold a good sized tire. I once had L60X15’s on it and they were sticky. Seems like the door sticker says G or H-78X15’s. I once had some H or seem like K or something, a really big bias ply tire called “Super Sports”, no name brand, but they were the stickiest tires I ever had on anything, seems like to the tune of 15K to wear out….but they’d make people grip the seat covers on curves.
I have the original 14 inch SSIII wheels on my 69 Cutlass. Great looking wheel but I’m going to have to figure out a way to upgrade to at least 15 inch wheels before too long in order to stuff a set of disk brakes behind the front two. In order to keep the original look of the SSIII it’s in the neighborhood of $800 each plus tires which I’m not sure is worth it because of the lack of options for rubber. Now I don’t kid myself, the cutlass is bone stock. It’s not a performance car (just a daily driver with some style that I can work on myself, and because of it’s age it is exempt from most of the bureaucratic BS which is very nice) but one of the things that I miss is the sense of confidence that comes with a good set of tires.
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Hi LF,
How about the factory Olds Rally wheels in 15×7?
Eric,
I’ve been keeping my eye out for a set of the 15x7s with the bolt-on center caps but they seem to be a rare item. I think that they were only used for two model years in the early 70s and they were an option. The reproduction of those wheels are the ones I found for $800 a corner.
But there isn’t a big rush to find them either. What I have works and there is always something else that needs to be tinkered with in the meantime.
I hear you, L-FL …
It is no easy thing to find nice condition original Rally (or other OEM) wheels for a reasonable price. Speaking of which, here’s a true story:
Back in high school, in the early-mid ’80s, my friend bought a ’71 GTX. It was a 440 4-BBL car, and it had a set of Hurst 14×7 wheels. Like the idiots we were back then, we took them off in favor of a set of Cragars. I don’t know what became of those wheels – my friend probably gave them away because (back then) no one cared and they were nothing special.
Try finding a set of Hurst mags today… and see how much they’ll cost you!