I'm looking at a set of Super Stock III wheels that came on 83-84
H/O and 86-87 442s for my 69 Cutlass. The stud holes in the
wheels are for 12MM bolts. My 69 still has 7/16 bolts. Am I going
to have to convert to 12MM bolts or is there an easier way I
haven't thought about?

HELP,
Owen

 

What SSIII wheels have 12mm bolt holes??
I have SSIII wheels on my car and nothing was needed to switch from 14x7 SSII to the 15x7 SSIII wheels.

 

No Oldsmobile of that era had metric studs.

 

The stud size is irrelevant. The hole is oversized and is designed to seat with a tapered lug nut. All that matters is that the lug nut has the right seat angle.
Also keep in mind that 7/16" is 11.1 mm, so you aren't talking about much of a difference in any case.

 

Joe, thanks for the response. Do you know of a lug net supplier
that offers the tapered nut design in 7/16 ? I remember selling
the 12MM nuts with the taper, but don't remember seeing a 7/16
version.

Owen

 

Any repro house selling the lug nuts for the 1964-77 cars. Fusick, Inline, Supercars, Parts Place, pretty much everyone. You can get the correct stainless capped ones, or you can get chrome plated. There are about a bazillion aftermarket vendors selling the latter. Speedway, Summit, Jegs, Amazon, Dorman, etc, etc.