What should I do?

As many of you know, I bought a 1965 New Yorker 2 door with a 440 engine. Clearly, this is not the engine that came in the car, but it is running and is a nice rider. I have done a disk swap, upgraded the suspension, got the alternator swap working, found a transmission leak and have my Coker's with Summit wheels. I could not have done it without you guys.
The differential is clearly stock. My mechanic told me that the car is a little overpowered with out a sure grip. He is not a Mopar...

What should I do?
Author: Boyd