So I originally posted in the engine swap forum about swapping to a 350 tpi, but after much consideration I am leaning towards going with a vortec 350(complete with all accessories, wiring harness and ecm) from a 96 and up tahoe, yukon, etc.

I read through the sticky about what is needed to go 305 tbi to 350 tbi, but does that all apply to the vortecs as well.

Secondly, there is a post about running the caprice tbi computer with a t5 and it says the check engine light will come on and the shift light will no longer work. Is this the same with the vortec wiring harness and computer since it wasn't offered with a manual transmission. If so, Does anyone know how to avoid this?

Lastly, if I use the wiring harness and computer from the vortec will I need to repin them?

 

Stock Vortec 350 I would just use your TBI with some 350 injectors and get a custom chip made for your swap. 350 knock sensor, ESC module, and chip should get you fixed up and be an easy swap. I have a friend that actually swapped in a Vortec 350 into a RS car using all the 305 stuff; injectors , esc module. stock chip, everything and he said it runs fine.

 

Vortec with a T5? Better install the T5 with wing-nuts. When it shatters you won't need tools to remove it.

 

Thank you dmccain,


does that mean I would just use my wiring harness or would I use the harness from the vortec?


Did your friend also have a t-5? I am not running on a track or anything so I am hoping the t-5 will hold up for a while.

 

Use the wiring harness you already have in your RS. You will have to get a carb style manifold and adapter for your TBI or GM parts makes one but its pricey. Im debating going this route myself but leaning toward just going carb again I haven't decided.Yes he has a T5. We all know it isn't the strongest but if your not power shifting at every light you should be ok. Ive saw a lot of em shattered even by 305s but they were being absolutely abused.

 

Thanks again! Yeah I have had a lot of people trying to convince me to just go carb, which I have considered, but I really want to keep it fuel injected if I could. It is not a daily driver and it is garaged for the winters so carb could work for me, but I want to keep it emissions legal in CT as well.

 

does anyone know what flywheel and clutch to use in this case. i have a 1986 trans am. i am planning a vortec 350 swap. and i have noticed a difference in starters and flywheels . so trying to figure out what exactly is needed

 

Your 86 should have had a 1 pc rear main seal. Just use a clutch and flywheel application your 86. But upgrade the starter. The 86 ones suck. I personally like the 92-97 era LT1 starters, any of them are vastly better. You can also use the vortec starter just fine, if my memory serves.

 

well the motor i pulled out was a 70s block. and im confused on the 168 tooth flywheel vs the stock 153 tooth. isnt the vortec flywheel bigger than a stock

 

168 vs. 153 is interchangeable if you also select the correct starter and clutch to go with it.

The important part is to get the balance correct: Neutral, or "400" for the two-piece seal bolt circle, or the one-piece cranks take a smaller bolt circle with a third offset weight amount. The big-blocks require still different flywheels depending on year and displacement.

 

ok thank you for your help

 

Ive had quite a few WC T5s behind “decent” 350s. My last one was in my 84 15th Anniversary, ZZ4 with an LT4 hot cam, 89 WC T5, 3.73s, and DRs. Left the line every pass at 3500, powershifted every gear. The car ran consistent 12.60s through the exhaust. Only thing I had was an aftermarket shifter and a CF DF clutch. Never missed a beat. Fox guys are still going 11s on stock T5 boxes.

 

All the tales you hear makes it sound like the driver sneezed and it broke. I'm not saying they're the strongest but I never had any major issue and it's been 20 years for me with a 350/t5 combo

 

Oh I know. It’s pretty funny to hear people talk about T5s. Granted the NWC were pretty soft, but so were the 350s in the late 80s-early 90s. Definitely nothing to write home about. I’ve seen T5s hold up just fine behind 350s, 383s, 400s, and even a mild LM7.

 

X3.

I had one behind a 400 that I drag tracked weekly, for 12 years. I flat-foot shifted every gear, every pass. In all those years, I broke a single, $12, 3-4 shift fork. I'll take that.

 

I have a non-WC t-5, I think it was rebuilt at some point before I got it but still. I wish more talk about them behind 350's made it around.

The fox body crowd isn't scared of them