6 lug rotor application?

Does anyone know? is there an actual application for a 67-87 Chevy truck that uses 6 lug rotors? I would like to purchase from my local auto parts store instead of having to order online from CPP and pay mega shipping charges. I'm doing a disc brake conversion on my 66' Thanks’

my 97 GMC 4WD uses them in front.
I think the 2WD has 5 lug.
Bob B

Thanks Bob, but I believe the brake design changed after 87'

You want to buy 6-lug rotors for your '66? Or do you want 5-lug rotors from a newer generation truck?

The 1988 changeover still had the 1500 2wd trucks with 5-lug rotors. Don't know if the bolt pattern is the same for your wheels, but they typically keep those the same.