corky9491

i' M HOPING SOMEONE CAN HELP ME OUT. I'M SWAPPING THE 700R4 OUT FOR A TH350, I HAD 3.73'S THAT I WAS GOING TO USE WITH THE 700 BUT NOW I DON'T WHAT TO USE THAT LOW A GEAR. ANY ADVISE WOULD BE APPRECIATED. THE CAR IS A 83 BERLINETTA, WITH ABOUT A 300HP 355. I ALSO HAVE A 82 PARTS CAR WITH A MIGHTY 4 CYL AND A 4SPD I WAS WONDERING WHAT GEAR RATIO THEY HAD.



THANKS CORKY

1SlowFormula

Corky, Lay off the caps!!! My calculator might be able to help you out if you choose the 93 fbody that has a 700, and compare it to a 350 that can be found near the bottom of the list..

what is wrong with running 3.73's in a th350?? My nephew is running 4.11's in his 72 camaor with a th350, it isn't too powerful runs in the 14's, and it tachs about 3300 PM's on the highway... What is the purpose of the car daily driver or race?

blownbird01

I've got 3.73's in my firebird with the th-350. I've got no complaints except for making 5# of boost at highway cruise speeds. Not exactly good an fuel, but who cares. Its a muscle car!

corky9491

blownbird, what kind of rpm are you running at 65, thanks corky

markinkc69z

Remember that going to the TH350 you'll be losing your low gear. 3.08 700R4 2.52 with the TH350. Say you have 350 ft lbs. In low gear you have 4020 ft/lbs at the axle. This is overly simplified, but play along. With the TH350 you will have 3289 ft/lbs. Thats an 18% decrease in torque for acceleration. So you should decide whether your main consideration is cruise rpm or acceleration. You will also lose your lockup converter so converter slippage at cruise is also a consideration, should only be 200-300 rpm with a typical street converter.

To get back the same low gear you would have to step up to a 4.56. That's the closest ratio available.

corky9491

Thanks guys, I know I'm asking alot but I would like the best of both worlds. My main goal is something fun to drive, I really don't want to run down the highway at 3500rpm.

blownbird01

at 65mph, I'm at about 3200rpm. That is with a 26" tire. Overdrive is nice, but my tranny does'nt break everyday like the 4l60. It was alot cheaper to put a pro built th350 in my car than get the 4l60e race prepped.