" 82 TSM sez that Spirit/Concord with 4 cyl putt putt has " 10.27" rotors. The six gets 10.88" rotors. Apparently same " caliper. Such a small difference, why bother? iirc the 4-cyl rotors were solid; the calipers used extra thick pads to make the difference up. ----------------- Andrew, you're thinking about the 77-79 2.0L. I don't know off-hand what the diameter of those are though. I suppose AMC didn't want as much braking force on the front of the four cylinder cars -- easier to cut down a rotor 3/4" than cast a smaller piston caliper. They could have monkeyed with the master cylinder bore, but then would have had to fiddle with the rear wheel cylinders too. So rather than have a monkey on a fiddle, they used a physicist and cut a rotor down instead... ;> Hmm... I wonder if it IS just a machined down rotor?? Wouldn't doubt it a bit... _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list