I have a 72 Nova I just baught on this site and the guy said the rear end is a Chevy 10 bolt 4:56 built. Thats all I have, I have not opened it up yet but my Chevy truck 1989 has a 10 bolt under it and looking at the 2, the one under my car the pumpkin is twice as big as the one under my truck. Is there different 10 bolts how do I find info on the one I have I am scared my new 550 to 600 Hp 427 is going to rip it out from under the car. Are there casting numbers? or any way I can dertermin just what i have