Best Rear Axle Ratio To Use With 700R Or 200R Transmission

[sweetolbob]

Joe

Considering the fact you have a 3:07 installed and you are using a 700R4, why even consider a change in the ratio until you get it on the road and have some experience. Put some miles on that combo and then you have a feel for the exact ratio desired. The 700R4/289 won't have any trouble moving the car.

Just trying to minimize the work to get it back on the road.

Bob

[JoeHall]

Joe

Considering the fact you have a 3:07 installed and you are using a 700R4, why even consider a change in the ratio until you get it on the road and have some experience. Put some miles on that combo and then you have a feel for the exact ratio desired. The 700R4/289 won't have any trouble moving the car.

Just trying to minimize the work to get it back on the road.

Bob

Good idea Bob. I just might try that. Though I once ran a 3.07 in a 56J with T85 for a while, before swapping it out for the 3.31 that is still in the car today. As I recall, the 352 Packard motor would pull it up most of the long grades in the SoCal Desert with the 3.07, without having to kick out of OD, but the engine just seemed happier with the 3.31. I believe Stude Corp offered the 3.07 pretty much as standard in the 1959-60 cars, even with the 259 motor. As you, I have no doubt the 289 would pull it, but am just thinking the 2.15 FD ratio in overdrive is pretty tall. It was a 2.21 before with the 56J, since the T85 is a .72 reduction in OD, versus the .7 in the 700R.
I have ran a 3.54 in the 62 GT now for about 270,000 miles, mostly with a T85, and with a 259 motor till recently going to a 289. I also towed many miles with that setup. I might just give your idea a try. Worst case scenario would be to swap it out later.

[wittsend]

I just did some checking to verify the Camaro ratios I mentioned earlier. Yes, they did use a 2.73 rear ratio with the 700R4 transmission. Depending on the year the tires were in the 215-225/ 15"-16," 60 series range. One post commented that "2,000RPM was 80 MPH." I'm sure some will debate the fact of a 80's - 90's Camaro being a "performance car," but that is the what Chevrolet was trying to sell them as. And, with performance in mind they felt justified in using the 2.73 gears in some cars and probably more typical 3.07 in others. I just throw this out there because I am with Bob that you should give the 3.07's a try. It seemed to work for Chevy.

Tom