Got some new wheels: Boss 338's in 20x10 and 20x8.5

[chuckmc8]

I think that I know whats going on here with the rotors. After 1988 all 5x5 rotors are 'stepped' on the hub like the Astro van rotors that I posted the pics above. i just looked up 88 & up applications for C/10, Van, burb and so on and all are stepped. prior years are not.
So the kwestion (my kue doesnt work on my keyboard) is there a way to run the later model rotors (88 & later) (ed:I have since found out there isnt)
I am running an 1986 crossmember with 2 1/2" drop spindles.

BTW, The coys dont fit w/o mods either. Here is a thread for reading with good photos on the coys. The 71-87 rotor hubs are the problem...after 88 I beleive the BOSS 338 or the Coys just bolt on w/o any mods
http://67-72chevytrucks.com/vboard/s...d.php?t=300737

UPDATE-I went to AutoZone and asked them to put an 86 rotor and a 88 rotor on the bench so that I could compare them- the 88 and later hub (and thus the spindle) is 1" shorter than the 87 & earlier stuff. That explains how the BOSS center cap clips in as designed. There would be ample room on the 88 and up rotor.
here is a 1988 & up rotor

The only other thing to check is if 88 & up spindles (with these smaller rotors & brake components)
would work on 67-72 suspensions.....if not, the grinding/lathe turning proceedure will be the only way to run these wheels.
Maybe useless info, but it doesnt cost anything to gather......and maybe help someone else