S-10 rearend

[trackster]

I have two S-10 rearends.  One with open 3:73 gears and one with posi 4:11.   Would like the 3:73 set in the posi rear.  Is there a way to tell if they are 7.5 inch or 7.65 inch without taking them out and measuring them?   Going to be running a 4L60E tranny and think the 3:73 ratio would probably be best for long distance cruising.   Will be the wife's car so probably not too worried about off the line performance.  I know these area not the strongest axles but she won't be flogging it either.

[enjenjo]

On the top of the right axle tube is a three digit axle code. You can determine what it is with  that axle code, and this list  http://www.lsxharness.com/336816530

[trackster]

Thanks for the link.   Nice info.  Found what I need.