Cast Year one 17x9 Snowflakes lug nut hol diameter - Come inside if you wanna know :)

[Henesian]

So, today I had the tires off my 76 T/A to change to DTC-30 brake pads in the front, and to cross-rotate the tires. I also had my Dad measure the lug nut holes, because I suck with calipers/verniers, and he's great with them. And They measured to be 0.750" almost exactly. And the stock 7/16-20 nuts are 0.704".

[Skip Fix]

I know the Year one repro 15x8s are exactly 0.750-so probably correct. Several of my old factory snowlfakes/turbo wheels are around .735 or so depending on wear. you are correct the factory nuts are around .700-.704. Factory rear axles and front discs use a hubcentric design to locate the correctly so it is not a big deal if you have a hub to centr them. Now throw on aftermarket axles with a short pilot and you lose that. Use 1/2" studs and after market lugnuts that measure .681 and aftermarket axles and the wheel can get tightened off center. My lug centric Pro Starts are only about 0.010-0.015 difference in the lugnut and wheel hole.

If you are using an aftermarket rear axle, or even a front hub that is not hubcentric you may need to make some lug nut bushings to center the wheel, or maybe a sleeve to locate it while you snug up 2 lugnuts. There are companies that make hub centric rings for wheels that are larger than hubs also.

[vintageracer]

Stock GM snowflake wheels used a factory shouldered GM lug nut. Same lug nut used on Mid-70's Corvette factory aluminum Wheels. These lugnuts are widely available from restoration suppliers.

Although I have personally looked at the year one wheel as far as lug nut holes year one may have cast the wheel to match the original GM lugnuts.

Something to consider?

[Henesian]

Stock GM snowflake wheels used a factory shouldered GM lug nut. Same lug nut used on Mid-70's Corvette factory aluminum Wheels. These lugnuts are widely available from restoration suppliers.

Although I have personally looked at the year one wheel as far as lug nut holes year one may have cast the wheel to match the original GM lugnuts.

Something to consider?Yeah, but the problem is that the stock lug nuts are so short, and the center of the rim is so wide, that the nut only goes like halfway in at best.

[vintageracer]

Yeah, but the problem is that the stock lug nuts are so short, and the center of the rim is so wide, that the nut only goes like halfway in at best.

Which stock lugnut?

Regular GM car lug nuts or Factory correct aluminum wheel lugnuts for the old style GM aluminum wheel?

The factory GM snowflakes were also "thick" and the stock GM aluminum wheel lugnut also did not cover/thread onto the complete stud. The centering shank for lack of a better term on the GM factory aluminum wheel lugnut that inserted into the lugnut hole on the factory aluminum wheel was only about 1/4 inch on the stock GM aluminum wheel lugnuts.

[LeighP]

Yep...the shank on the stock Snowflake wheel nuts does not go all the way through the wheel. The stock shouldered nuts should work fine on the YO 17" Snowflakes.
https://static1.pt-content.com/images/pt/2012/07/alum_wheel_lug_nut_k135-1.jpg