<BLOCKQUOTE>quote:</font><HR>Originally posted by USS Caprice:
... I was thinking about a performance parts crate too such as the base 350 HO as its much more powerful but I don't want to lose fuel injection - what would I need to support 330 hp with TBI?
To get to 330 fwhp with TBI you will need, at minimum:
1. L31 Vortec heads (1996-1999 truck 350 head)
2. Vortec/TBI compatible intake manifold
3. at minimum, a roller cam on-par with the factory LT1 F/Y camshaft (i.e. 201/208 degs i/e, 0.45" lift with 1.5 rockers). note that the Ycar LT1 was rated at 300 fwhp, and slight mods would up this to the 330 range, so the F/Y cam is enough to do the job provided you have very good heads/intake/exhaust. A bigger cam than the F/Y LT1 (or equivalent) will also do the job but at the expense of low-speed part-throttle driveability.
4. either the so-called "Ultimate TBI mods" per the http://www.thirdgen.org
tech article on a 305/350 TBI unit, or, the 454 TBI. The stock unmodified 305/350 TBI unit can support 310+ fwhp, so with minor mods to up the airflow, 330 fwhp can be reached. The 454 throttle body can flow more than enough air, as is.
5. 68 lb/hr injectors (at minimum) from a 92-93 LO5 9C1, or any injectors from a 454 TBI. The 68 lb/hr injectors would require the vFPR (see next item), while the 454 injectors might not depending on the size.
6. vacuum-compensated fuel pressure regulator (vFPR), discussed here and extensively on ThirdGen TBI forum. Also use a orifice damper (obstruction in the vacuum line with a small hole for airflow).
7. either a very big single exhaust using low restriction 94-96 style Bcar cats, or run the 94-96 dual exhaust (it's almost
a bolt-on if you use the 94-96 double hump trans crossmember) along with aftermarket mufflers. Or buy a complete dual setup for a lot more money.
8. cold air intake, either Caddy-style or dual snorkle.
9. Initial tuning of fuel pressure and ignition advance to get you in the ballpark; custom ECM would then be needed to smooth out the operation over the entire range of rpms and loads.
Understand that it can be done, but very few people have the patience to do all of the above and get it all correct. I'll add that you don't have to do ALL of the above to get 260-280 hp and 350 ftlbs, and that would allow you to run low 14s in the quarter. Shooting for 330 fwhp may be overly excessive, especially if you can run nearly as well with a lot less fuss.
FWIW I saw a '78 Caprice running a full ZZ4 carb'd crate motor that ran 13.9 in warm weather (and 13.6 in good air, per the owner), and Chris McCabe has a bone stock 95 Roadmaster LT1 engine
installed in his '89 and it's run 14.40 @ 93 or 94 mph. So a 280-300 hp 350 would easily park you at 14 sec flat. HTH.