Kagnus

L98 89'. Is this manifold worth it? I have heard it isn't any better than factory. SD claims 35 hp gains with the head/intake swap and another 75 hp if you add a cam. I wonder if the stock fuel pump can produce enough pressure to hit 375+ hp.

five7kid

If you're putting on Vortec heads and sticking with the TPI setup, you don't have much choice.

SDPC used to have a crate 350 Vortec TPI engine that used that base, advertised 360 HP (with Hot Cam, aftermarket runners, long tube headers, and 52mm TB). Not "big power", necessarily, but not too shabby, either.

Although I haven't done a TPI engine, from what I've heard and the investigating I did when I thought I'd be getting one before settling on an LT1 car, I would go with the Holley/Weiand Stealth Ram intake rather than an aftermarket TPI base. The SR is available in a Vortec version.

You'd probably want to upgrade the TPI fuel pump if yours is stock now. And injectors.

bjankuski

I cannot answer the question of how well the SDPC intake works on a stock engine. I did use that intake (ported by myself) on a 406 with a supperam and E-TEC 200 heads and it worked well. That combination makes 386 RWHP and 440 RWTQ and it pulls well to 6000 RPM.

MrWillys

I wonder is the loss in compression from the larger volume chamber is worth the better flow of the Vortec head?

Langma

I have this intake with gmpp vortec heads, crane powermax 2040 cam, and slip runners. Combined with no-cat exhaust and a correct tune, it's amazing how much stronger than stock the motor is. Great street combo...