6 lug rotors
 

i was wondering will 6 lug rotors from a 98 1/2 ton fit on 85 1/2 ton spindels and if any mods have to be done also will these parts fit my 70 1/2 ton gmc thanks for the info

Re: 6 lug rotors
 

That is way to complicated of a question w/o providing a lot more information.
I am going to "assume" that you are talking about 2 wheel drive....because you didn't say one way or the other.

So, in a word.....no.
Even swapping the '85 spindles to the '70 control arms would take some modification. The rotors are a completely different story.....metric to start with....and on from there.
Is there some reason you are looking for the six lug route? most guys are looking to go the opposite direction.

Re: 6 lug rotors
 

If you want 6-lug rotors, just get them from one of the board supporting vendors. They will bolt directly in place of OE disc brake 71-87 5-lug rotors.