305 TPI to 350 swap
305 TPI to 350 swap
hello I have a 91 Z28 auto that I am fully redoing and I want to put a new 350 crate motor in it. i just need to know what is the best motor to buy and what other things I will need to buy to complete the swap
Joined: Dec 2004
Posts: 16,892
Likes: 1,013
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 305 TPI to 350 swap
You should search threads and determine your budget .
High hp= more $$ for parts that will break trans, rearend. Adding
Sub frame connecters.
High hp= more $$ for parts that will break trans, rearend. Adding
Sub frame connecters.
Re: 305 TPI to 350 swap
I have read quite a few threads on here but I am wondering if the TPI set up changes anything. the majority of the swaps I found aren't TPI and I was hoping to see what crate motor everyone thinks is the best without breaking the bank.
Joined: Dec 2004
Posts: 16,892
Likes: 1,013
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 305 TPI to 350 swap
Staying with Tpi will require tuning. You can do this yourself, hire a tuner or get a aftermarket ecu dynamic efi ebl p4 etc..
Any changes should be retuned cam change /heads ...
Larger injectors depending on ho range.
You can always upgrade the tpi base runners , go hsr.
You should make your decisions on what you want power wise /torque range and budget.
You can go cheap and still a upgrade but not super .
Example a new gm crate Tbi 2 bolt main engine $1800-2k.
Bosh 3 22#hr injectors and have your ecm reprogrammed.
This would be a 200hp 350 not real great but it's new drop in and little mods to make it work.
You could step up to a vortec 350 , more ecm tuning would be required.
Cost is more for the intake, long block but 300hp would be acheavable.
Add a cam , headers.
Stroker 383 ! List goes on and on ......
Any changes should be retuned cam change /heads ...
Larger injectors depending on ho range.
You can always upgrade the tpi base runners , go hsr.
You should make your decisions on what you want power wise /torque range and budget.
You can go cheap and still a upgrade but not super .
Example a new gm crate Tbi 2 bolt main engine $1800-2k.
Bosh 3 22#hr injectors and have your ecm reprogrammed.
This would be a 200hp 350 not real great but it's new drop in and little mods to make it work.
You could step up to a vortec 350 , more ecm tuning would be required.
Cost is more for the intake, long block but 300hp would be acheavable.
Add a cam , headers.
Stroker 383 ! List goes on and on ......
Re: 305 TPI to 350 swap
I plan on staying under 3 grand I'm not trying to make a huge amount of horsepower just would like to have more than the 305. do you think it would be best to stay with TPI system or go another route? I really just need the most reliable setup so that I can take it out and on decent size cruises and not worry about issues with it
Joined: Dec 2004
Posts: 16,892
Likes: 1,013
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 305 TPI to 350 swap
http://www.jegs.com/i/Chevrolet-Perf...0282K1/10002/-
http://sdparts.com/i-23896057-sdpc-s...baseplate.html
https://www.southbayfuelinjectors.co...-d3-5-7-tpi-gm
I personally like efi for reliability, good power
http://sdparts.com/i-23896057-sdpc-s...baseplate.html
https://www.southbayfuelinjectors.co...-d3-5-7-tpi-gm
I personally like efi for reliability, good power
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Joined: Dec 2004
Posts: 16,892
Likes: 1,013
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 305 TPI to 350 swap
The memcal chip needs to reprogrammed , the 305 knock sensor should be reused it will not be the most accurate.
If it's a auto you could use a memcal labeled Anjf or aujp and a 350 ks.
Although these memcals are getting hard to come bye.
If it's a auto you could use a memcal labeled Anjf or aujp and a 350 ks.
Although these memcals are getting hard to come bye.
Joined: Dec 2004
Posts: 16,892
Likes: 1,013
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 305 TPI to 350 swap
There are a ton of other ways to go just do some reading research.
Joined: Mar 2000
Posts: 43,187
Likes: 45
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Re: 305 TPI to 350 swap
One option is to get a 350 shortblock and put all of your 305 stuff on it. One option is something like this from GM:
http://www.jegs.com/i/Chevrolet-Perf...61723/10002/-1
You'll put your heads, cam, lifters, sensors, accessories, and TPI stuff on it. You'll need new head gaskets (and probably other top-end gaskets). A new timing set is usually recommended as well.
Which exhaust system do you have, single or dual cat? The single system is lame, and will really hurt power on a 350 (it hurts the 305, in fact). If you have dual cats, you're good to go.
It would be best with larger injectors (although it will get by with the 19 lb in most situations). And a 350 tune since '91 is a speed density system.
Joined: Aug 2015
Posts: 196
Likes: 11
From: Salt Lake City. UT
Car: '92 RS
Engine: 5.0TBI
Transmission: TKX
Axle/Gears: 2.73
Re: 305 TPI to 350 swap
I'm just going to state what all the others are eluding to. Whatever you get, budget at least 1K more money to get it in and running. It could be even more if you have to change manifolds like the Vortec option stated above.









