Just to clarify:
73 to 76 A Body
4 1/2" (big bolt pattern)
I've only seen 10" front drums when drums were used with 4 1/2" bolt pattern.
(making all 4 1/2" bolt pattern 73-76 A Body cars to use the large upper b/j...disc or drum)

I have seen the 9" drums on cars as late as 76 when used with the 4" pattern as earlier mentioned. (/6 cars only using the smaller upper b/j typical to the 67-72 upper control arms)
runaway nervous musik drumhit

So are we in agreement or disagreement? shruggy

...FAFO...