Hey there, my 1960 rear end is finally discovered after hours of scrubbing off 42 years of grease and grime. The code on there is MA, I looked in my assembley manual and found that that rear end is the 3.90(no positraction) rear end used through 63 in the C10. I have a 3 spd tranny and a 350 chevy small block. Will I be able to go high way speeds in this or not? If not can I just replace the ring and pinion with lower gear ratio or higher not sure on that one. Please any help would be appreciated.