Chrysler's iconic 426 Street Hemi of the late '60s and early '70s was pretty unhappy if actually driven on the street. This engine - and others like it, including Pontiac's Ram Air IV and V 400, Chevy's aluminum ZL-1 427 and Ford's 429 Boss - were built for the track and didn't take well to idling in traffic. If you wanted a potent street machine, you wanted one of these:
* 1970 Buick GS 455 Stage 1
Don't be misled by this engine's seemingly mild 360 horsepower rating - be thrown back in your sport bucket by its stupendous 510 ft-lbs. of torque - more torque than any other engine of the muscle car era and all of it available at just 2,800 RPM.
For it is torque, not horspower, that moves a street car (especially a two-ton muscle car) down the quarter mile. In the case of Buick's 1970 GS, that task was accomplished in just 13.8 seconds flat at more than 100 mph through the traps. Zero to 60 took 6.5 seconds - if you could hook it up.
Those numbers make the '70 GS Stage 1 455 one of the quickest factory stock muscle cars ever built, period. And it delivered that performance with air conditioning and power windows, through an automatic transmission - and with civility few similarly high-powered muscle cars of the era could hope to match.
The Stage 1 engine featured a cold-air induction hood scoop/dual-snorkel air cleaner, high-flow 800 CFM Quadrajet four-barrel carb, large valve heads and a hotter camshaft, among other upgrades. It represented the pinnacle of Buick performance. Its 0-60 and quarter-mile numbers would not be challenged until the mid-late '80s and the introduction of the turbocharged Regal Grand National and GNX.
* 1973-1974 Pontiac SD-455
The SD-455 is considered by most to be the last hurrah of the classic muscle car era because it was the last V-8 that could honestly be called "high-performance," a specially-built engine with unique performance parts not shared with mass-produced engines.
Even when it was a brand-new engine, it stood virtually alone. By 1973 Ford, Chrysler and even the rest of GM's divisions (including Chevrolet) had killed off most of their true performance engines - and even the cars that once housed them.
The 290-310 horsepower (net) SD-455 Trans-Ams and Formula Firebirds built from 193 through 1974 were truly the last of the line. And they were also the most potent Pontiacs ever offered to the public - besting earlier bruisers like the 1970 Ram Air III 400 equipped GTO and the even more radical (and rare) Ram Air IV 400-equipped '70 Trans-Am when it came to getting through the quarter mile.
Even more remarkable, the SD-455 did it with low (8.2:1) compression and a mild hydraulic cam. So what was the SD's secret? Its radical round port heads that flowed more air than all the politicians in Congress combined. The engine breathed through a high-flow Q-jet carb and sent its exhaust gasses rearward via header-style cast iron manifolds. Blocks were SD-specific and featured provisions for dry-sump oiling to help potential road racers.
A stone stock SD-455 was capable of low 13 second quarter-mile runs and top speeds approaching 140 mph - with a non-overdrive three-speed THM400 automatic transmission (or non-overdrive 4-speed manual) and 3.42 rear gears. Uncork the factory exhaust, shoe the thing with drag slicks and dial up the ignition timing a bit and SD-455 cars were reportedly high 12-second machines. That is fast by any standard - even today's. A new Corvette is only slightly quicker - and it is advertised as having more than 500 horsepower. It also has the benefit of a modern six-speed gearbox and massive tires to hook it all up.
One wonders what the true output of the '73-74 SD-455 really was. And how fast it might have been with a bit more development - and better tires to put all that grunt to the pavement instead of brutalizing the overmatched 15-inch rubber that came on the cars of that time.
* 1970-1972 Chevy LT-1 350
When the 350 small-block Chevy V-8 appeared (along with the also-new Camaro) for the 1967 model year, it was as a mid-performance engine - above the Camaro's standard inline six, but several steps below the big-block 396 that was available in the Camaro SS. By '69 (final year for the first-generation Camaro) it was still playing straight man to hot dogs like the Camaro Z28's race-intended 302, which could be ordered with exotic equipment like a cross-ram four-barrel intake, with cowl induction, tube headers and chambered pipes in the trunk.
But as wild as it looked - and as great for high-RPM SCCA roadracing as the 290 horsepower 302 may have been - it sucked on the street. It wasn't very driveable, didn't work with an automatic transmission (none were offered on production cars) and wasn't even especially quick, either. Stock '67-69 Z28s were generally good for low-mid 15 second quarter mile times.
All this - and the so-so reputation of the 350 - would change in 1970, when the LT-1 appeared in the Corvette and as the new "second generation" Z28's standard engine. Though it still offered high-performance special equipment like the previous year's 302 - including an aggressive solid-lifter camshaft, high-compression pistons, four-bolt block and an aluminum high-rise intake with a Holley carb on top - the extra cubic inches gave it both superior horsepower (370, according to the press releases) and streetability.
It was also a better performer than the old 302 - capable of getting a '70 Z-28 through the quarter in the 14s. Not only was the new Z28 noticeably quicker it had much more part-throttle punch. Buyers also now had their choice of either a 4-speed manual or three-speed turbo-hydramatic, too.
Unfortunately, the LT-1 had a brief life due to ever-increasing emissions regulations and was replaced just a few years after it was introduced by the much milder L-82, which lost the high-rise intake, Holley carb and aggressive camshaft. It was still a decent performer, but couldn't match the brutality of the LT-1.
* 1966-1972 Chrysler 440 Magnum/Super Commando
The 426 Street Hemi may be Mopar's rock star engine, but like so many other extreme engines of the muscle car era that were basically race car engine "detuned" for the street - and put into production to legitimize their use in race cars - the Hemi was not at its best poking along in traffic. In fact, it wasn't really happy outside of its native environment - the high banks of NASCAR super speedways like Daytona or ripping up the asphalt in quarter-mile bracket racing.
Hemi cars still get the big bucks today as collectibles, too. But back in the day, savvy street racers knew the virtues of the 440 - in either Magnum (Dodge) or Super Commando (Plymouth) forms.
Its rated peak horsepower - 375 at the peak of development - was not too far off the pace of the Hemi's 425 horse rating (though admittedly, the Hemi was probably laughably under-rated). But "on-paper" numbers or no, the 440 delivered heroic performance in 4,000-lb sheetmetal dreadnoughts that had no business being fast.
The single four-barrel 440 was a tough customer, but for a few years, one could up the ante with a three two-barrel carb setup known as the Six Pack which pushed the rated output of the mighty engine to within striking distance of the vaunted Street Hemi. The three carb set-up got cancelled after '71, however - and though the 440 block continued in production through the mid-late '70s, it got crippled up after '72 and continued to lose special parts (and performance) until the end, when it was just a big engine for big boats, all hollowed out and barely belching out 200 honest ponies.
* Ford 289/302
Ford has built a number of standout V-8s over the years, including legends like the 427 and 428, the 390 and 351 Cleveland - and of course, the 429 Boss. But unlike virtually all the muscle engines of the '60s, Ford's sweet small block - the 289/302 - lasted as a production engine for decades after the original muscle car era ended. It was in fact still powering Mustang GTs as recently as the mid-1990s - and was only retired after Ford concluded it could no longer be tweaked to meet constantly tightening emissions and fuel efficiency requirements. Ford's new 4.6 liter overhead cam V-8 took its place in the Mustang for the '95 model year. Thhough not a bad engine, it lacked the low-speed grunt and muscle feel of the old pushrod/OHV Five-Oh.
Like Chevy's also-excellent small block V-8, the 289/302 was a very versatile little engine that could be built for economy and smoothness (in two-barrel form, with mild cam - just like Chevy's 307, 305 and even a few 350s) or it could be set up as a full-tilt screamer with a 6,000 RPM-plus redline and more horsepower than it had cubic inches.
Early Mustangs with the K-code 289 "Hi-Po" (and its advertised 271 horsepower) are among the most desirable of '60s-era muscle machines - capable of quarter mile times right there with the big block bruisers (14.68 seconds, according to one road test of the time). Ford's small V-8 also held the line during the darkest days of the mid-1970s, keeping at least the idea of V-8 street performance alive (if not the actuality).
And when the second muscle car era flickered to life in the early 1980s, it was Ford's Mustang GT - powered by a 5.0 liter "Boss" - that led the way.
I have built a few 289's in the past. One that has turned out very good for me, would be the 289, bored .040, using a 302 steel crank, using 289 rods, with 302 pistons. I've been told that this basic set up will not work. Well, it has for me for about 11 years now. I've only broken one engine because I over reved it. It hit 9500 rpms before it said "enough of this crap", and sneezed a piston. Other than that they run very well.
9,500 RPMs? With stock 289 rods and 302 crank?Originally Posted by J. ZIMM
Ok, I'm impressed!
I knew these engines were free-revving (6,500 RPM safely possible with the right pieces) but never would have tried 9,000-plus.... or even 8!
For real?
As a side comment: I have a 455 (Pontiac) in my Trans-Am. This engine is a very long stroke design and anything over 5,400 RPM is generally not advisable. On the other hand, torque is its virtue. The 400 meanwhile, will rev much higher - and is more a "high-performance" engine in the sense that it likes to see the high side of 5,000 RPM when built properly. The two engines have very different feels to them. I like both, though for different reasons.
Most non-Pontiac people don't know, incidentally, that Pontiac never made "big" or "small" block V-8s. A 350 Pontiac is visually (externally) exactly the same as a 455. Displacement differences were achieved by altering bore and stroke.
I just read the "Great Muscle Car Engine's" article, while it's pretty good, I wonder why some engine's didn't get mentioned, or barely glanced at, like Fords 428, in the SCJ or CJ form, it was a very good performance engine, and in my personal opinion, far better than the "Boss" 429, as the 429 needed a lot of work to really shine, ask Taska (ask me sometime about my track testing the 1969 No. 7 Tasca Ford "Boss" 429 Mustang, after a Restoration in 1999), and nothing was said about the solid lifter 396's found in the Chevelle's, Nova's and Camaro's in the 60's, early 70's (402's), or the LS6 454 found in the 70 Malibu's, or any of the Pontiac Ram Air 400's, produced in far larger numbers than the SD 455's.
Even the L-79's (327 / 350 h/p), found in a few Chevelle's and Nova's, weren't slouch's either, nor were the L-48's with 300 h/p in Nova's and Camaro's, although to be truthful, Mustangs, Cuda's, Challenger's, Nova's, Camaro's and Firebirds are Pony Cars with Muscle.
Also, Dr. Old's W-31's did pretty good too, and Ford's "Boss 351" Mustangs hit in the middle to high 13's, a pretty good showing for the heavier Mustang they resided in.
Oh, and I believe it was the 1996 model year that Ford put the 4.6 engine (W an V code), in the lineup for passenger cars, including the Mustang, not 1995.
Just my take on it.
Rex
Click here: Morley's MuscleCars and MuscleBikes - Your Muscle Car Headquarters!
Hi Rex,
Welcome, first of all!
On the engines: This is a very subjective subject - and so people will naturally have differing opinions. To me, a "street" engine means, for the most part, no solid lifter cams (and valve adjustments every few weeks), which excludes many of the higher-horsepower muscle engines of the '60s and early '70s. Many of those engines, while they produced great power, were also peaky, had weak low-speed torque and thus not-so-great street drivability. In other words, 1/4 mile times were not the sole criteria, or even the primary one.
(Per the above, the LT-1 may be a little iffy; its successor, the hydraulic cammed L82, may not have had as much power but was a fine street engine. On the other hand, the LT-1 did work ok with an automatic, vs. the old 302, which did not!)
I much prefer the Q-Jet to the Holley for a street car, too. Holleys are great all-out performance carbs but when it comes to cold-start performance/drivability, a properly set-up Quadrajet is very hard to beat... .
On the Pontiac V-8s:
The SD-455 had low compression and a fairly mild hydraulic cam - so it worked well with an automatic transmission, AC, and was exceptionally streetable. Yet it outperformed the 455 HO and the previous RA III and RA IV, the latter of which had solid lifters and was marginal as a street engine. The '77-79 W72, "T/A 6.6" 400 was also a good street engine. (I've owned/driven several of these myself over the years.)
Buick's 455 Stage 1 is another example of what I would call an outstanding street muscle car engine: docile and "wife drivable" - yet capable of 12 second quarters in nearly stock trim in a 3,800 lb. car.
I agree with you on the L48 350 Nova SS - great package! Ditto the Oldsmobile 455.
PS: We'd love to hear about the Tasca Fords!
Last edited by Eric; 03-31-2009 at 08:33 AM.
Eric -
Did the 1977-79 350 Firebirds have the Pontiac V8 or a Chevy small block under the hood? In a previous post, I lamented that they seemed slow compared with those in years past.
In 1996, I bought a brand new Mustang with the 4.6L engine. It was rated at only 215 HP, but it still provided decent acceleration. The 1996 was my absolute favorite year for the GT, as it had the right combination of interior colors and a smooth engine.
It was a great car that could out accelerate most vehicles at the time and could get 26-29 mpg on the highway at 80 mph. If I hadn't let someone else drive it one night (who wrecked the car), I would still be driving it. (Don't ask about the accident, as it is too painful to talk about!)
Pontiac did indeed make its own 350 V-8. In fact, the 400 is simply a larger-bore 350. Same stroke; same almost everything else. Heads, intakes, exhaust, etc. all interchange directly. An early performance version of the Pontiac 350 - the 350 HO - was a Firebird offering in the first generation ('67-'69) models and was a great engine. And of course, the last "real" (Pontiac powered) GTO, the 1974 model, had a 200 hp 350 4-barrel with functional shaker hood scoop.
The mid-late '70s 350s, though, were economy oriented and had two-barrel carbs. But they were Pontiac built!
Last edited by Eric; 04-01-2009 at 07:01 PM.
Back in '95, Ford let me have a Cobra for a week. Now, these were the real deal - race-ready with the last of the 351 V-8s (NOT the 302; not the 4.6 OHC engine... a 351 Windsor) tied to a Tremec five-speed stick - and next to nothing else. No power windows, locks or AC - hell, these cars didn't even have insulation!
Drove that SOB to NYC from DC at ridiculous speed in the middle of the night. 135 mph through the Baltimore Harbor Tunnel, the exhaust reverberating off the tile walls.
Good times...!
Last edited by Eric; 04-01-2009 at 07:02 PM.
Nice. In Alabama, mine got up to 138 mph. Had more pedal left. Could have done 145 or so.
It was a great trip; one of my most memorable! Of all the new stuff out there, the Mustang is as close as it gets to the way American cars once were, in terms of balls and soul. The new Challenger has this quality also, but it's sure to be gone after next year - if not before.
My 1992 Mercury has a 4.6 in it. So Ford did have that engine back then.
Yep. If memory serves, the last year for the 5.0 in the Mustang was '95.
'96 was the first year for the 4.6 in the Mustang.
Or so I recall!
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