"Assumption is the Mother of Error".....the critical measurement is the width....on my 54 it was 62" which required a rim with a 4" backspacing. Measurement is from rim mounting surface to mounting surface.

R&P ratio is simple. With one wheel blocked and one free to turn....mark the drum at 12:00 and mark the Yoke so you can keep track of both marks. Turn the drum 10 rotations while you count the turns of the yoke. Example: 10 turns from the drum equals 18 turns of the yoke.....DOUBLE the number of the yoke (36) turns and divide that number by 10 which ='s 3.60. This is for a non-posi diff.

Just a suggestion....I've used the 80's Camaro diffs in my 54 truck....most common R&P ratio is 3.42 and 3.08....3.73's are a little scarce. They are plentiful and inexpensive...require cleaning off the coil spring mounting brackets and some shims straps to adapt the 2-5/8" axle tubes to 3" U-bolts. The stock Camaro sway bar will easily adapt to the AD frame (39" from eye to eye) and 1-3/4" spring perches are available from Tractor Supply or any trailer shop. If you go with a S10 T5 upgrade the shortbed S10 driveshaft is a good fit and will bolt up without changing any u-joints. Check out my diff mods in my webshots. It's a great way to open up the diff, get a great R&P ratio and works.

Dave

Webshot "Tips and tricks" and "Shoebox" Photo Albums

EXPERIENCE is the best teacher...but it gives the test first...and the lesson afterwards.

"What this generation tolerates...the next will embrace"