Sorry guys but need help again please. I have a 51 that has a oldsmobile 350 with a turbo 350 automatic tranny and it has a stock 1955 rear end. My cruising speed at about 65 mph is turning around 3100 rpm. It has the factory 3.90 gear ratio. If my calculations are right if I change over to 3.08 it will drop rpm's about 500 or 600. My question is can this be done. I would also like to change it to a posi-track. Is this possible or have I gone crazy. I need to get my rpm's down so I can cruise on the highway. Thanks for help everyone.
