I have a 1948 chev panel truck and have put in a gear vendor overdrive. it work great but I think that the 456 rear end is being pushed to hard and thought that I could drop in a 411 ring and pinion. Will that help or not. I believe that it is a 456 and without taking the back off the rear end can I turn the drive shaft and mark the wheel to know what I have for sure and if so how.
Thanks for your help