Swapped in a trans am disc brake rear. Had to borrow an axle from the old drum brake rear to replace a stripped stud.
Question is this. It appears the drum axle is slightly different. It has a small lip on the flange where the rotor/drum fits over. And it appears that it would keep a disc rotor from seating properly (Haven't bought the new ones yet, but the old one didn't fit) So, am I correct and if so I see 2 solutions, 1-go to boneyard get a trans am axle or 2 - grind/machine the rotor hole a little larger to fit correctly.
What do you think ?

Pretty easy to replace studs. I'd try that first.

Drum axles are not the same lenght as disc axles, so even if you machined down the hub the rotor and caliper would not line up correctly.

great...this rear has caused me more trouble and down time...now a trip to the boneyard. Thanks for the input... I have been wanting to go "hunting" for a while now.