Sure grip diff

[Wyo65Coronet]

I want to put a sure grip diff in my '65 coronet 440 4dr, but not sure what size axles it has.

It's all original. Motor is a 383 (for sure!) and 727 trans (I think?)

Please help me out!

Also, what offset do I need for 18" rims? Don't want to move springs or shorten axles.

 

[5.7 hemi]

Axles are 30 spline, and your gonna have to measure to get the correct offset for your particular tire and wheel size.