It is cheaper and better to just use a donor from a newer truck. Done it several times. Just measure your WMS-WMS and search internet info to find some that come close. Then buy one on Craigslist. Be sure to open it up before buying to inspect gears and ratio. $100-$200 for open diff. Easy install. Some shock mount mods may be necessary.
Supposedly: NOT verified,
69 and some 70's 62 1/4"
71-72 and some 70's 63 3/4"
1955-1959 Chevy Pickup 62"
A little wider is OK and can be compensated with
Backspacing/off set adjustment.


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