What Ratio and what Tranny?

[jstork69 0]

I just bought a 69 Sprotsroof that runs really strong from 0 to 60, it is turning almost 4500 RPM @ 60.

 

I was told that it was a C4 with a shift kit and a 4:11 9", I bought a 3:50 to replace hoping that would give me some more drivability but it turns out it is a 3:00 to 1 3rd member currently.

 

HELP!!!!!!!

 

I am pretty sure that it is the tranny causing the wind out but changing the ratio is a lot easier (and cheaper), how low should i go or am I wasting my time?

[MDinDestin 14]

The shift kit just firms up the shifts, it doesn't change the ratios.

 

The 4:11 rear gear is downright uncomfortable at highway speeds and is bad for fuel economy and engine wear. It may be tolerable with an overdrive transmission, but is too steep for my tastes even then.

 

You're on the right track with the 3:50 although I personally wouldn't go any lower (higher numerically).

 

The 3:00 is what most of the 69 and 70s came with from the factory.

[bnickel 10,004]

you're turning 4500 at 60 and you have a 3.00:1 rear? did you actually check the gear ratio physically or are you just going by the door tag? with a 3.00 and a c4 you should be turning about 2800-3200 depending on tire size

[MDinDestin 14]

It didn't make sense to me either so I assumed he bought the 3:50, but didn't install it after he learned it was really a 3:00. ???