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Hi folks, would someone out there be able to tell me what manual box do I need for my 3970010 engine, its taken me 54 years to get my 1st C3 and am very new to this car, I am doing a full rebuild wheels up and one of the things that has had to come out is the Auto box, so I am now looking for a manual to get this beautiful car back to as close to original BUT on a small budget. Have played for many years with all sorts of of cars/vans but NEVER with one of these so I would be very happy to receive someone else's knowledge. many thanks.
If your car is a model year 1969 through 1973, it would have the 3970010 engine and a Muncie. If a1975-1979, it would have a Borg Warner T-10. If a 1974, either one - early production was with Muncie and late with B-W. Not sure of the transition.
Install a Muncie...whatever model you have. Or, even better, install a 5 or 6-speed box. You will be glad you have the overdrive, when you're traveling at speed.
Well I don't know, I have a Super T10 with well over 100 thousand miles on it. Replaced the rear yoke and seal at about 45 years old. That's it. It's been absolutely reliable.
And boy oh boy have I been hard on it!
The Muncie and Super T10 were good transmissions. Similar in strength but won't last in drag racing or harsh use. For street cars they're good. The ST10 has some more ratio options. You need to know your engine RPM range and what rear gear ratio you have. Most automatic cars had 308 gears, not too good with a Muncie, better with the ST10 264 WR trans.
335-355-370/373 are better gears for manual trans, unless you have "BB" torque.
I ran a 2.52 1st gear wide ratio muncie with a 3:55 rear gear on my LT-1 for 30 years. It was a great all-around combo for a good revving small block.
That was an original 2.20 close ratio box 4:11 rear gear car. I absolutely hated that gear. Could not cruise anywhere over 50-55 mph.
The 355s handled 70 mph interstate trips.
And the total ratio for 1st, 2nd and 3rd was EXACTLY the same in both setups!
Only used 3 gears at the dragstrip anyway.
With the close ratio box you need at least 411s.
The wide boxes work much better on the street.