ls1 to a TH350... how?

[V]

ok, what do i need to make it work? i'm gonna be running a LS-based motor with a TH350 behind it which i have laying around. Ive heard of adapter plates, spacers etc, but can someone point me in a more clear direction? maybe even with links to vendors? Motor will be basically stock so just a mild stall would be needed.

[JSPERFORMANCE]

bolt pattern is the same. where is the problem?

[johnjzjz]

the throttle cable ratio of travel might be different and than the shift timing will be off - plus a T 350 is a very weak unit far from a real choice with the work needed -- but if you go for it the convertor has to be kept no more than .100 from the pump ( install it all the way in and pull back out no more than .100 or pump issues will happen -- and the D shaft yoke is 30 spline - jz

[JSPERFORMANCE]

I am not sure I agree with you about the strength thing John.. I have two th350 cars out this season that go into the single diget et range. One weighs 3250 the other a little heavier, both street cars. We just freshend the one trans after over 300 passes and the band was the only part that really wore down, but otherwise no breakage. So if built correctly they can hold up decently..

[V]

Originally Posted by JSPERFORMANCE

bolt pattern is the same. where is the problem?

ah ok, i thought so but kept hearing other things. is there then a spacer needed for the flywheel or somethign special for that?



and John, im not too set on the TH350, its just a builtone i have laying around. i didnt think about the kickdown and all. I could use a stock ls1 auto trans instead, that'll easily handle the mild power levels i am going for. I'd just have to buy one so thats a few more hundred, oh well.

[JSPERFORMANCE]

use a manual valve body then there is no kick down or vac modulator to worry about.

[V]

ah ok. im still in the planning stages for the car, the engine mockup will hopefully get done by november, then itll be at least a year and a half till any more progress is made on it. pesky deployments....

[ins0mnia24]

My buddy uses a th350 w/ transbrake in a 402 LSX car runs 9's never has any issue's but it was built for its application.

[johnjzjz]

JS the 350 band is only in play during a manual downshift to second so i guess you shift the car up and down kind of defeates the purpose of an auto matic -- hahhahahahhaha
having owned a trans shop years back if it were not for the 350 trans and others like it we never would have made any money we carried 25 of them in stock at all times their were days we swaped out 5 or 6 of them alone - maybe it was the NYC drivers that killed them the stock ones today their are all kinds of beafed up parts for all the units -

sss- after pulling the conv out the required .100 you shim the distance to flexplate with washers or spin off some spacers on the lathe - street car > steel -- race car alum alloy, or titanium -- jz

[Pampered-Z]

Never done one, heards it's allot of work and not really something good if the car is street driven as the manual valve body is a PITA as well as you shorten the life of the trans?

Things you need to address:

1) Crank spacer.
2) Trans mount adapter.
3) Modify factor flexplate mounting holes.
4) Speed-O adapter.
5) replace trans dipstick tube.
6) Modify shifter.
7) Repogram the computer. (might need to also swap to a Manual trans ECM)

Below are things I'm not 100% sure of.

** might need ** some year F-bodies need a trans with a 9" tail shaft on the trans or you need a custom drive shaft.

Shift pattern on valve body (Front facing?) is use if you want to use a modified factor shifter, if not you need an aftermarket shifter.

There is a company called FITZALL that sells a kit that contains most of what you need.

If the car sees allot of street use you would probably be better off modding your stock or a 4L60E to handle the abuse. Seems like a better way to go, just as strong as a 350 plus you get better gas milage.

[V]

if i can find a good deal on a stock 98-02 auto trans ill go that route.

its not going into and fbody so all mounts, DS, and shifter will be new/aftermarket anyway.

[ins0mnia24]

Just make sure if you go that route that you get a 4L60E from a V8 car because the internals are a little different between V6's & V8's for power output reasons along with the input shafts are for different size converters..
I just went through a rebuild last spring it took 2 work order papers to cover the amount of parts that went inside of mine..

I keep this for 4L60E reference material
http://www.theimportkiller.com/4l60e.pdf

And this site I also keep for reference material these guys have alot of info, tranny parts and swap kits for LS based cars th350, th400, 700r4, 4l60 & 80e ect..
http://www.transmissioncenter.net/highperflist.htm

[V]

Originally Posted by ins0mnia24

Just make sure if you go that route that you get a 4L60E from a V8 car because the internals are a little different between V6's & V8's for power output reasons along with the input shafts are for different size converters..

yea, id def get a V8 one... cuz the v6 version wouldnt bolt up to an LS motor

[badzracing]

I had a RMVB 700r4 in my truck ( 6.0l/ ls1 based). I also had a regular 700r4 in it before that with hydraulic lock-up and a tv cable /bracket from bowtieoverdrives. I ended up with a t-400 and you do need a flexplate spacer. Look on ls1tech and performancetrucks.net. Every once in a while I see people selling the spacers fairly cheap.

[mc73nova]

Car Craft , October 2008 Edition. There is a whole article about getting the early style transmission's on new style blocks. I have it in my hand right now if you can't pick one up I can e-mail you the article, if you want.