Howdy!

I'm gathering parts for the LS1 rear disc brake upgrade on my 66 with a 70 chevelle 12 bolt differential. I have a questions for those of you that have made the swap: It looks as if the wheel mounting pad on the rotor is a bit shallow and will end up moving the wheel mounting flange location a bit inboard relative to the factory drum brakes, yes?

In simpler words, will the LS1/4th gen rear disc brake conversion also result in moving the wheels inward a bit, and if so by how much exactly relative to 12 bolt drums? Thanks so much!

With my swap the disk is a tad thicker than the mounting face of the drum so it actually moved the wheel out about 1/8"

the wheel will get pushed out by the difference between the thickness of the drum mounting flange and the rotor mounting flange- so maybe about 1/4" per side.

1/8" extra per side is what happened for me....