BitchinRS

I am going to be swaping my 3.1L for a 400sbc and have a few questions.

1.) Can I retain my T5? I know I will need to swap the bell housing, but will the input shaft match up? I don't want to swap over to an automatic.

2.) Head choice. I want trq. and plenty of it!!

3.) engine mounts. what am in for when comes time to blot this baby in. Do I need to make custom mounts?

4.) Exhuast. what size pipes, and what headers will be best.

5.) Induction. I need to keep it looking stock. 5a.) will a 350 TPI setup bolt up. 5b.) if yes will it choke this poor engine so bad I would be better of with the V6?

Thanks!!!

CaptPicardsZ28

I have a 400 which replaced my 305. The tpi will choke the crap out of it even with porting. The intake is only good to 4500rpms. After that the fuel will flat line. I went with the HSR. Running 30# ford svo's with a custom chip. Bought the hsr intake, plenum and fuel rails. Huge difference from tpi. I have super comp shorties with 3" exhaust w/no cat into an 80 series flowmaster 3 in and 3 out. You can drop the motor right in. All sbc's use the same location for mounting. Not sure about the t5 tho. Maybe someone else can help with that. You may have to use a different flywheel or flex plate???

ljnowell

I believe the t5 does work, just needs a bellhousing swap. But, dont shoot me if I'm wrong.

wesilva

iTrader: (35)

You want to retain the V6 T5 AND you want plenty of torque...OUCH!!! Kiss the T5 goodbye. It is rated at something like a dismal 200 ft/lbs. A bone stock 400 has twice that much torque!! A World Class T5 would be your least expensive alternative. Then grab a pair of V8 frame mounts. You should already have the appropriate holes already in the frame. They are the holes closest to the front of the car. Here's a good recipe for a torquer.
http://www.chevyhiperformance.com/te.../148_0306_406/
Full length headers are best but more expensive. Shorties will kill a little torque but your going to have your share.
A stock 350 TPI can barely keep up with a stock 350. Plan on some upgrades.

five7kid

iTrader: (14)

Emissions testing and inspection - yes?

Your best bet is to abandon the 400 idea and go for an LT1 with six-speed. Smog it as if it's the car the engine/tranny came from.

wesilva

iTrader: (35)

Can't argue with that. GM actually considered a run of 602 LT1 powered third-gens for the final 1992 year that used mainly parts from the factory parts bin. The GM Race Shop built one from a 1991 Z28 before the project got scrapped because of cost considerations. It was featured in several magazines including Super Chevy March 1995. There are a few third-gen owners on this site with the Lt1 swap that can offer advice.

BitchinRS

Yeah just did some reading on emisions laws regarding engine swaps in Calif. Has to be same year or newer. I figured I all ready had the 400 and would go with it, but I gueess thats out of the question now. DAM!!!.


I didn't know there was a difference between the world class T5 behind the V6 and V8 other than the bell housing. I want to stick with at least a 5 speed. I would like the 6 speed but it may be out of my price rang after doing the engine swap. May have to wait a while for the 6 speed upgarde.

Thanks!!!

tta1415

I was thinking about the 400 swap too as I have a 92 Z with TPI, would the TPI even fit up to the older 333882 casting heads on the 400?

wesilva

iTrader: (35)

This article should help. It addresses the intake or base manifold issue somewhat but sounds like a pre 87 base manifold or complete TPI is the easiest route to mount the 400 heads. How about modifying the 92 Z heads to use on the 400? Is it a 305 or a 350?

http://www.sethirdgen.org/tpi1.htm

tta1415

Thanks for the link, the car is a 305.