There's also several different 10 bolts used in both Passenger and Truck, with differing ring gear and housing sizes. They range from the 7.5/7.6 found in S10s and '78 and late mid size to the 8.6 found in late model GM trucks. Parts do not interchange exept within the ring gear size families.
An option you might consider would be to find a new 3rd member for your existing housing. That will keep a reaend you know will fit right. The 3rd members will swap '55-'62.


Bill Burmeister