Rear end ratios???
Thread Starter
Racer
Joined: Oct 2005
Posts: 469
Likes: 0
From: West Slope of the Sierras California
Rear end ratios???
I've looked at everything I got with my '73 and can't come up with a rear end ratio. Came stock with the 190 HP and Muncie. Anyone have any ideas what I could have?
Thanks
Thanks
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
The 4 speeds usually came with a 3.36. Someone could have changed it or a different one could have been ordered. The best way to tell is jack it up and count the driveshaft revolutions with exactly one turn of the tire. 3 1/4 turns is a 3.36. 3 turns a 3.08. 3 1/2 turns a 3.55 and so on.
Burning Brakes
Joined: Aug 2004
Posts: 856
Likes: 2
From: Tyler Texas
In all liklihood with that engine/trans combo your 1973 is a 3.36:1 ratio.
Code LR or AX is 3.36:1.
Differential cases and covers both have casting numbers and a casting date. There is also a "stamped in differential production code" on the very bottom rear edge of the differential case adjacent to where it meets the cover. The differential production code begins with 2 letters--this code will tell you which gear ratio you have. Look for LR or AX. (Sometimes it is easier for me to read in the dark using a flourescent light. )
A single letter will follow the production code which denotes the assembly plant. Then a date of assembly code, then a letter indicating the source for the unit, then the assembly shift code--in other words there will be a series of letters and numbers.
AA is 3.55 AB is 3.70 AC is 4.11 AW is 3.08
Code LR or AX is 3.36:1.
Differential cases and covers both have casting numbers and a casting date. There is also a "stamped in differential production code" on the very bottom rear edge of the differential case adjacent to where it meets the cover. The differential production code begins with 2 letters--this code will tell you which gear ratio you have. Look for LR or AX. (Sometimes it is easier for me to read in the dark using a flourescent light. )
A single letter will follow the production code which denotes the assembly plant. Then a date of assembly code, then a letter indicating the source for the unit, then the assembly shift code--in other words there will be a series of letters and numbers.
AA is 3.55 AB is 3.70 AC is 4.11 AW is 3.08
