1971 Original Front Disc Brakes?

[sKnNyPpY]

Hi All, I'm new to the board and need some expert advice. I have a 71 GMC 350 Longbed with 2.25 leafspring rear and disc fronts. The last owner said the front end was from a 72 but I have doubts. I measured the front disc and it is 1-1/8 inch thick. Not 1.25. Markings on rotor say: 1.215, K6, L60, 3963998. Markings on caliper say: G25, I8. 1" studs approx 5" apart. Can you help identify my front end, I'm looking to get some drop spindles, etc? THANKS!

[Katrina/10]

Disc brakes were standard on a 71.

[sKnNyPpY]

Thanks, That's what I thought. PO just let it rust and was going by what his PO said....Could 1-1/8" disc thickness be 1.25" worn down?

[ChevLoRay]

1.215....is that stamped into the disc somewhere? If so, that should be the minimum thickness. If you measured 1 1/8th, then that would be 1.125, which would tell me that they have been over-cut or turned too many times, and are too thin.

As for the distance between studs, don't measure adjoining studs. Instead, measure the distance center-to-center of two studs with one stud between. In essence, when you tighten up your lug nuts and you tighten opposite nuts....well, that's the way you pick two to measure. Don't measure across the dust cap, tho. It'll throw you off. Or, you could go by a parts store and ask them for a guage. They're usually paper and are free.

[sKnNyPpY]

Thanks! Time for new rotors before anything else!