engine wiring diagram chevy 1998 454

I don’t, but have you tried searching online? I’ve been able to find PDFs of the factory shop manuals for all my vehicles, including old (30-plus-year-old) motorcycles… I’d try this route first.

Alternatively, the common Haynes or Chilton’s manuals that you can pick up at most auto parts stores usually have wiring diagrams, too. Not as detailed as the factory manual, but pretty good. These repair manuals usually sell for about $20 or so.