ive been doing searches on a th350 swap for the last few days, and two things i havent been able to find.

#1- do i need to change my fly wheel, right not i have a 350 with a 700r4 behind it, i dont know how many teeth the flywheel has.

#2- do i need a new torque converter or can i use the one on my 700r4, if not what would you recommend for a mild 350 street car?

also just to make sure, will i be alright with a 3:42 rear end, ive been told the 3:73 will rev high , but i think the 3:42 should be good.

thanks for any help.

 

1. No. it will work fine, except that you MIGHT have to elongate the TC bolt holes slightly. (slightly different diameter bolt circles)

2. No you cannot use a 700 TC in a 350. You will need a PG/350/400 one.

3. 3.73 gears are fine. That's what the factory used for YEARS AND YEARS behind 350s. 3.42 is OK too. In either case, I would recommend a smaller diameter one (porbably 10") with a stall of around 2400 RPM, which will keep it in its fully coupled mode at any kind of reasonable cruise speed. The reason for a smaller TC is that in order to raise the stall of a large dia one, the "slip" is usually MUCH greater when it's supposed to be coupled, and the stall is somewhat "vague". With a smaller one, it can be made to be looser below stall, stall more suddenly and consistently at the desired RPM, and couple more tightly above the stall speed.