I've never seen an 8" with 5.5 bolt pattern. 8.8 sure...but not 8". A 9" from a pickup would be perfect. That's a good plan, GB, and you'll be glad you did it.
__________________
"It don't take but country smarts to solve the problem" (Smokey Yunick)
'41 Merc Town Sedan / 260" 8CM engine
'66 Fairlane four door / "warmed up"

302