1971 Camaro Z28 Lug Nuts
 

Have checked through threads and have not found answer to confirm correct lug nuts used on 71 Z28? I know they are 5/16 - 20. Can anyone confirm originals were 13/16 or 3/4 socket size? Picture would be great. thanks. Mark

I would think they were 7/16 and possibly 3/4 socket size ...

Just as the pictures show posted earlier. 3/4 hex nut. 7/16 stud. 70 to 73 on camaro z28. In 1974 they changed design. They are used on other GM car lines also such as 71 72 chevelle ss share them. Also I've seen them on 69 hurst olds. Very rare to find on any car, even survivor cars. They were not made well and the jacketed caps came off. Usually discarded early in life on most cars.

Someone recently paid 2k for a 1970-71 set too.

1971 Lug Nuts
 

Thanks. Saw some guy has originals on EBay for $135 per nut!!!!

And his are the 2nd design.

Actually, the ones on eBay are the 1st design, but posed next to a second design so you can see the difference.

https://www.ebay.com/itm/GM-NOS-Cama...19.m1438.l2649

Note: I have no affiliation to the seller. Just posting the link for informational purposes.

When at this years MCACN I didn't see any cars that were supposed to have these actually have them. Not that there weren't any, I just didn't see any.
Very hard to find. Charley's survivor LS-6 may have been the exception.

This is one of these parts that you would think there would be a boat load of NOS out there. Pretty much the first time you hit them with an impact they shred the jacket. The dealers I would have thought would have had a bunch in constant inventory to replace them. I guess they just ran through all the first designs pretty quick and most didn't notice back then the change to the second design. There are probably survivors out there that have a mix of both on the car.

Not even realizing there were 2 different styles, until reading this thread. I went out and checked my 70 Z/28, and found exactly 10 early ones on the front & the 10 on the rear were the later style Hmm !

Wow. You certainly don't want to have a mixed up car. Probably not even safe to drive. Here's what I'll do. I'll trade you even 10 second designs for the 10 first designs! I'll even pay shipping. Waddaya say?:naughty:

Funny thing, I just checked my 70 Z that I've owned since 1987 that only had 36K miles on it and I also have 10 early style on the front and 10 second design on the rear. Weird.

Not too weird. Probably shows that the back tires were changed out more often than the fronts and the tire shop destroyed the original nuts. Considering the car and its tendency to spin the back wheels, totally expected.

When I bought the car in 1987 it still had the original tires on it and original spare never on the ground. Obviously the rears were worn a lot more than the fronts. I bought it from the original family. My car is a June built and I don't know when they started using the second design. I have a low mileage Ls6 that is a July built and it has all second design nuts on it. Does any one know when they started using the second design?

Watch out on using the re pop 2nd design on original 1st design wheels. The angle on some of the re pop lugs is different and I found some that did not secure the original wheels properly. Wheels and holes were in good shape for 47 year olds but did not fit tightly. Just a watch out. Mark

Dave,
Second design lug nuts were as far as I know introduced in the 74 model year.
My parts history books show the first # 399683 superceded to 414188 in July of 74.
My brothers 73 Z28 still has most of the first design lug nuts still on it.
Chris

Thanks Chris for your expertise. The second design nuts on my Ls6 are borrowing there way into the rim so much that the stainless cap is touching the rim from previous owners tightening them too much. Jeff told me you can repair but then I'd have to paint the rim so to retain the original paint I use part number 9591780 lug nut that is a captive stainless with a 60 degree seat which sits nice in the hole with out sinking into it. The appearance is really close just a little taller. Safety first!

The 2nd design LOW CROWN was not used until 74 at the earliest.

The 73 Assembly manual shows the 414188 lugnut as a running change in March or April for the turbine style wheel -which I do not believe actually came on 73's, though it is shown in the 1973 Camaro assembly manual.