If this works the backing plate needs about 1.75" spacer
I'm thinking that spacer needs to fit tightly on the axle and be made of some substantial stuff, because the last thing you want is your backing plates moving around and breaking bolts or brackets.
How would you feel about actually welding the spacer to the axle?
Does any of the brake mechanism move into possible contact with the hub as the backing plate moves outward 1.75 inch?
Do you know what year your axle is? I just looked up brake drums for mine on Rock Auto using a '79 P30 as the vehicle and found the same drums used across a number of trucks from '73 to '84. The pictures look like the same drums you found at NAPA, though I don't trust parts dealer photos quite that far.
We are supposed to have temps in the 40's today and I'll try to get outside and look at and measure things. Otherwise I'm back in the hospital tomorrow and away from my toys at least a week.
I agree, the spacers will need to be substantial, probably made from a solid piece of steel.
They will need to pilot off the flange and have a pilot for the backing plate on the other side.
I considered making new flanges, essentially moving the existing ones, but then they really need to be trued up after welding, I don't have a lathe long enough to swing a whole axle housing.
Bolting on the spacers and then welding them to the axle tube seems like a great compromise.
There is lots and lots of room to move all the brake stuff in toward the hub, no clearance problems there.
I don't know what year my axle is. but GM used only a few different hubs and brakes on the 14 bolt, all this stuff is amazingly common and interchangeable. I was guessing 1988 for looking up parts.
Good luck tomorrow and next week, I know what you're going through is no fun.
Grigg
