I'm running a '67-'69 Camaro 12 bolt(same as Nova,Firebird, I believe) under my '46 panel.Spring perches lined up, fabed shock mounts.These are the narrowest, 10" wheels and 295's protrude a bit, 8.5 would go under the fenders.Right now the 12 bolt -posi is probably worth more than the whole rest of the truck, but a non-posi 10 bolt should do much cheaper.