Re: ??? on parts
The 2004-R came in most GM RWD cars with the 3.8L V-6 engine, most notably the 83-87 Buick Turbo cars -Grand National/T-Type Regal(and in my opinion the only 2004-R I'd use.)I don't think that GM used them behind any V-8s though I could be wrong though. I think they started using them around 77-78 and continued up to like 88 or 89. The 4.3L fuel injected TBI engines were first offered in 1987 Astro/Safari mini-vans, C/K fullsize trucks-base engine, and 87-91 Caprice RWDS, and of course 1988 S-10/S-15 Jimmy Blazer. I don't think they were ever offered in K-5 Blazers or Jimmys though. The 2004-R should be an easy find in any junkyard as thats where most ended up and the owner might even let you have it for free! You can build them up though as witnessed by me from an 8 second GN running 15Psi boost with a mild trans! Just look up the TurboRegal webring, tons of parts-transbrakes, airshifters, kevlar bands&clutches, rev-manual valvebodies, almost anything you could want! Good luck.