I got my 59 ton finished the other day finally. It runs great. But the 70's 350 turbo tranny and the original 59 speedo aren't jiving too well I guess I need to change the plastic speedo gear in the tail section of the tranny. I put a nice tach in the cab so I can check my rpm. At 2000 the speedo says 80mph I know that's wrong. What I need to know is what the true mph would be at 2000--3000 rpm. I have a semi stock 283 with stock 350 turbo tranny and stock 5.14 rear end. I'm worried about the rear end being stressed at any high mph. I'm gonna use the tach to tell me how fast I'm going to keep everything from blowing up. Cause that would be bad Does anyone know the formula for rpm to mph
