heavy duty 150 notice the rear does not have the hubs sticking out of the rear wheels like the 250 trucks do thats an 8 lug 9 1/4 rear just has a higher gvwr then a 5 lug 150 truck it will have heavier springs and bigger brakes also.
I've seen 250's without the hub sticking out as well, unless someone when through alot of effort to change a 1/2 ton thats a 3/4 ton with 150 badges, likely because the old ones fell off the fenders