I was thinking you are most likely going to have to piece that rear suspension together from a couple of sources.
Since you are in Tucson and apparently just getting started on your resto - you might want to get in touch with Bill Speer, Member 4326, there in town. He has a parts business on the side an would most likely be a lot of help.
I checked Franks Pontiac Parts in So Cal and they did not have anything. Another person with a large parts yard for Pontiacs in AZ is Steve Barcak who puts together the annual Pontiac Heaven meets each spring in Phoenix. He hangs out in the Performance Years forums.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
