12 bolt rear ratio
 

Blew the rear end out of my 84 Silverado. My right rear wheel almost fell off going down the road and there is a 5 inch hole in my diff cover.

I have a replacement 12 bolt from a 79K10. I popped the diff and counted 47 ring and 16 pinion. Is it just me, or is that a lot of teeth? The math comes out to 2.94. My Silverado is 3.08. I'm hoping this read end is 308 also. Any tips?

Re: 12 bolt rear ratio
 

I'd say check your count again, they don't show that ratio in the catalog.

Re: 12 bolt rear ratio
 

I counted it twice. I don't know the history of the donor vehicle though...

Re: 12 bolt rear ratio
 

46/15=3.07 ~ 3.08
Count the gooves instead of teeth.
The big ring will have number stampped on it.

Re: 12 bolt rear ratio
 

47 and 17 is a 2.76. That was a factory ratio offered. I haven't heard of the numbers you listed. If it is indeed as you counted it then you should be close enough.
Frank

Re: 12 bolt rear ratio
 

The number of teeth should be stamped on the ring gear. The one shown is 14-43 which is 3.07.