I have been searching for a Sure Grip 8 3/4 - 3.23 - third member. I have an add running with a picture of what I am looking for just because I had too many odd ball requests.



I have someone who replied with the following:

"I have a diff. like that,,not sure what ratio is..came from a 73 or 74 Roadrunner..440"

How can we tell the gear ratio ? The casting #'s will tell me if it is a 741, 742 or 489 correct and whether it is a sure grip or not ??

Of course I assume someone could have changed the gears as well over the years ?

No idea how to find out what exactly this is ?

thx,

stuck

 

Yep' It is stamped in the ring gear

 

there will be a part number on the pass side of the housing next to the yoke, the last three digits tell you what type of case it is, 742, whatever.... the gear ratio will be stamped on the side of the ring gear , thats the big round gear on the inside of the caes, look at it from the drivers side of the case, then turn the yoke, it will then turn the ring gear, its round and has teeth cut in it. there will be a series of numbers and letters . then youll see something like, 3.91 of 3.23 in that series of numbers after a small space, thatll tell you the gear size.

 

thanks again all