I have an 88 cutlass supreme, I pulled the 307 and 200r4 tranny and put in a mild build 350 with a turbo 350 tranny with a blue plate? shift kit. I plan to run the stock rear diff and drive shaft just to break in the motor. Will the Diff and drive shaft hold up to the power if i were to jump on it? The motor is fresh bored 30 over, dish pistons, one step up from a stock cam, w-31 #5 heads, edel performer intake with a 650 cfm carb.

 

Yeah, you'll break the 200-4R first.

The valve body plate isn't the problem on that trans. It's the internal hard parts that need to be upgraded.

 

I believe you'll be fine unless you beat on it like a rented mule.

 

The 350/TH350 combo is a good one and should deliver decent torque. Your drive shaft specifically the Ujoints and rear end are now the weak link. Both should hold up for break-in unless you have wrinkle walls and do a smokey burn out at every stop sign.

 

Sorry, I missed the fact that you were installing a TH350 with the 350 engine. Forget what I wrote.

 

I was told that a 7.5 10 bolt open can hold up to 400 ft lbs, with street tires.

I had a 7.5 open with 3.42's behind a 350/400 combo and I drag raced the car. My 350 was a stock one from a 68 Delmont with a 7111 manifold

 

Thanks for all the replys and info guys. Helped alot! Thanks