I've been wondering and info is hard to find, but does anyone have a good idea of how much weight you gain when upgrading to a 9" or 12-bolt rear end?

I know the 9" outweighs the 12-bolt, but not by how much.

What about 9" rear ends with aluminum center sections? How much weight do you drop? Is there a significant strength tradeoff compared to a total iron/steel rear?


Thanks

 

Actually, the 12-bolt is heavier than the 9". I remember reading it was something like 12 lbs more. On average.

 

I think I got this from Hot Rod's web site.



If you subtract the weight of the drum brakes the 12B is a good amount lighter.

 

how do you differientiate between what bolt a rear end is? Which bolts do you count? I know I am ignorant, but bear with me.

 

It goes by the # of bolts on the diff cover.

Many people believe in error that it is actually by ring gear bolts...but all 3 14-bolts have 12 bolts holding on the ring gear. A more specific way to to denote a axle is by the ring gear size (like a ford 9") because there are many different size 10-bolts, and 14-bolts.

 

that cover is the one in the middle of the axle that faces toward the rear?

 

yep

 

Add 14 pounds for the torque arm mount