If i just changed out the rear gears in the stock rear, would the torque from the 350 v-8 tear the rear end apart? That's why I was thinking of upgrading to a later model rear, something late 60's to early 70's.
The only gears available for the factory rear are 3.9:1 and 3.38:1. The factory rear should hold up to a 300hp/ 300 lb torque 350 small block. Any more power than that will rip the housing apart.
I am with red58. There isn't much advantage to change from 3.9:1 to 3.7:1. However, if you have a well built motor, you will need a stronger rearend to hold up behind it.
