For originality sake, I'd rather not put a 5 speed in my '67 OTS. Has anyone out there changed their dif ratio to a 3.07? If so what do you think? How's the take off? Having never driven my car, I do not know what to expect from the stock ratios. I heard that you can pull stumps with the stock ratio..

Herb

 

Three common ratios are 3.54:1, 3.31:1 and 3.07:1

I did convert my 1966 4.2 Coupe 3.54:1 to 3.07:1 but my brother drove the car before I got a chance and totaled it racing a Corvette.(17 year olds!)
Kinda wish I could have experienced 'more than 120MPH' with the 3.07. (the acceleration was amazing with 3.54)

 

My UK 4.2 series 2 is a stock 3.07. Acceleration fine, no problem off the line, and can still pull away from 20 mph in top gear smoothly. But cruising at 70-80 is much easier than on a 3.54 or similar. Most people in UK try to switch to 3.07 if they have an import with a 3.54

 

Mine is a UK-spec 3.07 rear as well, and I too, love the longer gearing. The torque of the 4.2 has no problem with it, and it is much more comfortable at highway speeds. I think that one could get 2.88 gears (maybe for the auto?), but I don't have experience with that..