Hello all....I am doing another V8 swap.
I am currently debating wheather to go Tuned Port injection or maybe the SFI L31 Vortec. I already have a complete TPI 350 from an 89 Iroc. But I know a guy who will give me a complete good running 1998 Vortec 350 for it. Painless Wiring sells a harness for both....so wiring would be a snap either way.

Which would be better? I don't have a lot of money for perfomance upgrades so my question is.......which is better stock?

I think the stock Vortec engine output was higher around 255HP/330TQ. Vortec heads definitely flow better. But I like the TPI look much more

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Palm Beach Fieros
http://pbfieros.tripod.com

quote Originally posted by Alex4mula: ...But I like the TPI look much more

I agree with you there.

I vote TPI

according to msn auto the 89 iroc made 175 HP and 255 TQ and the 5.7L V8 in 98 C/K 2500 made 255 HP @ 4600 RPM and 330 TQ @ 2800 RPM. Giving the choice I'd go with the vortec 350.

quote Originally posted by foxxman25: according to msn auto the 89 iroc made 175 HP and 255 TQ and the 5.7L V8 in 98 C/K 2500 made 255 HP @ 4600 RPM and 330 TQ @ 2800 RPM. Giving the choice I'd go with the vortec 350.

That's wrong for the 89 TPI. Those numbers are for the non-TPI 5.0. The 88 Pontiac brochure has the 5.0 at 190HP (auto) 215HP(manual) and 295TQ (auto) 285TQ (manual). The 5.7 is 225HP 325TQ. The 89 should be at least the same. So the Vortec makes some more HP as we all should expect. Fix the intake a little or better yet get a better cam and you will be there if you like the TPI. Mine is putting 236 rwHP and 344 rwTQ

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Palm Beach Fieros
http://pbfieros.tripod.com

[This message has been edited by Alex4mula (edited 12-01-2005).]

The stock vortec intake is fugly and I am a vortec fan. I would still do the vortec swap to get the additional power and then plan to make it pretty later as you ge the $$$.

$$$ can cure the uglyness.
There is a lower TPI manifold for Vortec Heads that is around $350.

Or you can get one of these (GMPP RamJet setup with everything except harness and ecm for $1,600):

Yea, not pretty.........but I think I will go ahead and trade up my TPI for the Vortec. I like the idea that it already has good heads and sequential injection.

quote Originally posted by v8fiero400: Yea, not pretty.........but I think I will go ahead and trade up my TPI for the Vortec. I like the idea that it already has good heads and sequential injection.

I did one of those several years ago. The engine was out of a 2000 Chevy Van that was damaged during a railroad ride to the dealer.

I had Street & performance use a TPI harness & put the injector connecter plug (that big plug in the middle) from a Vortec harness on it. Also used the Distributor from a TPI type engine.

Turned out pretty good.

Archie

quote Originally posted by Archie: I did one of those several years ago. The engine was out of a 2000 Chevy Van that was damaged during a railroad ride to the dealer. I had Street & performance use a TPI harness & put the injector connecter plug (that big plug in the middle) from a Vortec harness on it. Also used the Distributor from a TPI type engine. Turned out pretty good. Archie

Thats a good idea..... espescially to save money (...the Painless Wiring harness for the Vortec is expensive!!!).

The only thing I don't like about going that route is that you would go from sequetial fuel injection to the older, slightly less efficient, "batch" fire injection.

quote Originally posted by v8fiero400: Thats a good idea..... espescially to save money (...the Painless Wiring harness for the Vortec is expensive!!!). The only thing I don't like about going that route is that you would go from sequetial fuel injection to the older, slightly less efficient, "batch" fire injection.

Something that isn't publicized is that most of the SFI systems are only sequential at idle and low RPMs - as the engine speed climbs, they switch to batch fire. The "efficiency" gain from SFI systems is really only available at idle...