Thanks Mike that helps alot,Good to know that I can cruise.

Originally Posted by Mike B
The 2-speed in the '57 has a high gear ratio of 6.40:1 (low is 8.72:1). If you have 9.00x22.5 tires they are about 35" tall so your speeds will be as follows;

at 2000 rpm = 32 mph

at 3000 rpm = 48 mph

at 4000 rpm = 65 mph


If you have 10.00x22.5 tires they are about 39" tall so your speeds will be as follows;

at 2000 rpm = 36 mph

at 3000 rpm = 54 mph

at 4000 rpm = 72 mph


This calculater doesn't care how many cylinders or how much HP you have, it's all about RPM.

My 1956 Tow Truck with a 350 sbc and a 2-speed runs 65 mph all day long.

Hope this helps.

Mike B smile