Thanks everyone, I sourced some HD spindles today from a local yard. If anyone is looking for standard duty spindles, rotors or calipers, I have some that are available.
Thanks again.
From 88 through maybe 91, there were standard and HD brake options on 2WD C1500's.
The differences are the calipers (2-1/2" piston vs. 2-15/16") and the rotors. The HD rotors take larger bearings and fit on larger spindles and of course take different bearings.
I have a 1990 GMC SWB Stepside, single cab 2WD that has the standard duty (light duty?) front brakes.
I'm changing them over to HD, have everything to do this except a set of HD spindles. Seems these should be plentiful as everyone who installed lowering spindles should have a set of stock...