I am looking to replace the lug nuts for the SSIs on my ’70 Cutlass S – they’re the capped ones and have gotten pretty beat-up over the years. Lots of parts dealers offer them, but I’ve seen a few dealers (Fusick for one) list a different nut specifically for SSIs – it’s solid chrome with a spherical head, not a flattened head like the capped ones. I’ve not seen spherical head lug nuts used on SuperStock wheels – does anybody have any info on them?

My Assembly Manual shows only one lug nut for A-Body custom wheels (part #399683 – I assume this is the capped nut), so I’m curious where this other nut comes from.

 

All that matters is the thread, the depth, and the "seat" of the nut(taper were it contacts the wheel). If the thread is right, and it's deep enough to hold the stud, and it will seat on the rim properly, it will work.

 

I was thinking in more of an historical context: did all SSIs come from the factory with the spherical head lug nuts? That’s what the Fusick catalog seems to indicate. If so, why do so many SSIs seen today have the capped nuts? The spherical head nuts are twice the price of the capped ones, could that be it?

I haven’t seen many ’69-’72 Cutlasses with SSI wheels in person recently, so my only reference is pictures on the internet or on TV (those Mecum Auto Auctions on HDTheater make a good reference). From what I can tell most SSIs have the capped lug nuts like mine. Anybody out there have the spherical head nuts on their wheels?

 

I know this is an old thread but I am also looking for the correct lug nuts for 72 SS1 wheels. I don't trust parts vendors descriptions since there are times when they have been wrong

Are they the round top?

http://www.fusickautomotiveproducts....p?number=WN713

Or the flat top?

http://www.fusickautomotiveproducts....p?number=WN714

Warren

 

I would call Fusick to confirm. They are the best vendor for Olds & should be able to give accurate info.

 

The factory parts book is the place to get accurate information.

There are three applicable lug nuts shown in the parts book.

391399 Used 1965-68 on "first type chrome wheels", shown as "acorn type"
399683 Used 68-70 "super stock second type" and all 71-72, shown as "stainless steel cap"
414188 Superseded 399683

EDIT: This is apparently a picture of 391399, as used on the 1965 RPO N98 chrome wheels. Spherical ends.




This photo shows the difference between the original 399683 (on the right) and the currently available 414188 (on the left). The height of the hex and the tapered section are completely different.



Bottom line is that the OP's 1972 does NOT use spherical head lug nuts.

 

Fairly consistent with what Joe said, my very first car was a '69 4-4-2 holiday coupe with SSI drum brake wheels. The lug nuts on it were the stainless steel capped type, shown on the right side of Joe's picture. Of course, I bought it when it was 3 years old but I don't imagine that someone would change the lugs from the "first time chrome wheels...acorn type" to the stainless steel cap type in that short of time.

Randy C.

 

See edit in my post above for spherical end lug nuts on the 1965 RPO N98 chrome wheels. These must be the 391399 lug nuts.

 

This is the same lug nuts that Troy Thornton of Thornton Classics was selling for SSI rims on eBay.

 

Unfortunately, their listings are incorrect, as I note above from the parts book data. They show the sphericals for 66-72, but they are correct for 65-68 (SSI only). The others are the incorrect factory replacements for the correct stainless capped nuts used 68-72. Unfortunately, I've not found a source for the correct ones.