Inliners International Forums General Discussion Drive Train th350

I have a 1960 biscayne that I am putting a 1970 250 into... It has a three on the tree, and I was wondering how much work it would be to replace with a th350 trans.??? If it is not to much work, it will cost about the same as putting the three back in... Any help would be great...

Lee, changing to a flexplate and bolting up the TH350 is easy. When I originally put my truck back on the road, I flipped it to a 350 from a three on the tree (it was seized).

The starter is the only thing I could see being a problem. If it's already block mounted, then no problem, but if it's trans mounted, you better check that your block is drilled for a block mount starter, since the TH350 uses block mount. I don't think you'll have an issue with a 1970 250.

You'll also need to add a tranny cooler (your rad may not have any built-in cooler), plus you'll need to hook up the kickdown cable. Make sure the 350's vacuum line is hooked up to good manifold vacuum. I originally teed mine into the PCV valve hose (it was convient at the time), but this didn't work because the PCV valve bled off all the vacuum.

Good luck,
Greg

You shouldn't have any problems regarding if or how it will fit. 1970 Chevy's used the TH350 so floor and other clearances are fine.

Just my perspective on things: why not keep it a standard but use a 4 speed? I find rowing through the gears a lot more fun and it gives your left leg something to do while you're in the car.

You must already have the clutch pedal and all the linkage if the car is now a 3 speed.

OOPS!!! My apologies! You said it is a 1960 car NOT a 1970. Of course the TH350 wasn't around in 1960.

Also the driveshaft yoke will need to be changed for the TH350. Interestingly enough this is the same yoke used on the Muncies, Saginaws, and the all sychro 3 speed trannies. So down the road if you do a tranny swap from one of those to another that will stay the same.

700r4 yoke too, thm200c,

basically all gm trannies are 27 spline output except for 4 speed toploader trucks(sm420 and ch465 etc,) and th400's 32 spline


i put a 12.5" plate and starter from an 80-up 305 engine on my 1968 250 engine and it works great, its the starter nmose with bolts inline, one short bolt and other long, i have all the parts i saved them off the 250 yesterday when i loaded the engine up for scrap, saved the manifolds and other parts too, engine got water in it it was a remanufactured one, fixable but i cant right now,. so to shredder it goes,

if you need plate and starter i can mail them to you, they are in excellent shape the engine was a good runner


good luck

One other item you will need is a shifter. If you can find a steering column from an automatic it will be easy to hook-up the linkage or you can go with an aftermarket floor mount unit. It would also be nice to find a pedal assembly off an automatic car as they have a larger brake pedal than a manual car.

Bummer, I just bought a 250 with a 350 behind it out of a 1977 Nova. Other than the short block, I'm not going to use any of it! Arm