Rear brake question

Assuming you have a 8 3/4" rear you can drill your axles to the 4 1/2" bolt pattern along with your brake drums. Drill and tap the holes for 1/2" screw-in studs as you will not have enough room at the edge of the axles for press-in studs. Using 7/16" press-in studs will give you about 1/8" of material left to the edge...spooky!

If you are purchasing new axles this would be the perfect opportunity to swap to larger brakes. Your brakes are 10" X 1 3/4", assuming you have a 8 3/4". Picking up brakes from a larger car gives you 10" X 2 1/2" drums. If you look hard enough you can find the 11" X 2 1/2" drum set-ups. Make sure it has the correct 5 bolts attachment (backing plate to the axle tubes). If the rear end you are taking the brakes from is a 8 3/4" then it'll fit. Do your homework if it's coming off a different rear end as it will probably not fit your 8 3/4". Later model cars went to the inspection cover type rears (8 1/4, 9 1/4", etc.). In my opinion, this would be the CORRECT and should be the only way of changing your rear wheel bolt pattern.

BTW, I don't think the Volare/Aspen spindles will work on your car. You need to look for a 73-76 A-body disc brake spindle. Hope this helps your project car.