Chevy P30 Chassis 1973 brake rotor clearance.

FWIW, The rotor is too thick for the brake pads to go on. I know - I SHOULD HAVE CHECKED THIS FIRST! - I measured about 15 dimensions on the old rotor before buying this one - knowing that I was buying one marked '75, not '73. All dimensions matched up, except rotor thickness, which I didn't bother to worry about since I knew the old one had been ground. I can't tell if this rotor is really different - made with a thicker rotor - or if it's just manufacturing tolerances. A lot of searching hasn't really cleared it up. I have a Chevy chassis and engine manual, so I'm going to hunt through that. The shop (that was going to do the rotor regrind) said they could find the right part with my VIN. I hate grinding off a lot of valuable rotor surface just to make it fit, and I particularly don't want to do it if this rotor is different in some other way.

if anyone has any info on the P30 motorhome front rotor - dual real wheels - for '73 vs '75, please feel free to post it.