C-body 8-3/4 or truck 8-3/4 rear

Looking for the BIG length 8-3/4ā€ rear found in the C-bodies from the 68-72’ range or the pickup 1/2 ton same age range.

I’m trying to find this rear axle with in a close range to Connecticut.
All I want is housing, axles and a center chuck. I can take it from there. Brakes are a bonus. I want to convert the 5x5.5 bolt circles(current axle) to 5x4.5 bolt circle for a better selection of rims.

Thank you,
Syleng1
Every c body 8-3/4 I have ever seen is 5 on 4-1/2 already, nothing to convert there