Shelby Cal 500 rim questions

[68cuda]

Picked up a set of (4) original Shelby Cal 500 all magnesium rims with original Shelby center caps for my '68 Barracuda Fastback, 14x7, 4 1/2 inch large bolt pattern. Previous owner claimed he had them on a '68 Charger. They do not have a beveled center hole- not center hole centric - or beveled lug nut holes - not lug centric.

Anyway, does anybody know:
1.) What length and shoulder thickness lug nuts to use? (IIRC 3/4" length?)
2.) Standard Mopar wheel hubs are 2 13/16" diameter (71.4375 mm) and the Shelby Cal 500 center circle seems to be 79.5mm or 80mm - what IS the exact center circle diameter of the Cal 500's? I'm have a heck of a time getting a good micrometer into the wheel center to measure it (dial micrometer is too long).
3.) Are hub centric rings required to make sure the wheels are centered because of the difference in hub diameter and wheel center circle diameter? It seems that not using them would put a heck of a load on the lug studs since the wheels are neither lug centric nor center circle centric and stud breakage would be an issue.
4.)Any other tips / inputs from guys who have used Shelby Cal 500's on their A-Bodies?

 

[diymirage]

Good looking wheel

 

[68cuda]

Thanks. I like slotted mags. And as a bonus I scored a set of genuine magnesium wheels.
Been doing some more research on the web and getting creative with measuring since it appears the wheel and tire companies won't commit to any suggestions or solutions via phone or email on older wheels and types of wheels they do not currently stock or sell due to possible liability issues.

So far what I have determined - and I hope this helps somebody else too:
1.) the wheels require lug nuts with a 3/4 inch shank (the wheel center is 7/8 inch thick and has lug nut holes 11/16 inch in diameter). The dimensions I have come up with so far that will work : Standard Mag type lug nuts with shank and washer, 1/2-20 RH thread, 3/4 shank length, 11/16 inch shank OD, washer OD 1 1/16" (available online at Summit).
2.) the Shelby rims I have measure 78mm in the center bore as near as I can tell using improvised calipers then measuring the caliper spread with an accurate micrometer using thousandths of an inch and converting it to mm. The standard mopar hub is 2 13/16 inches which translates to 71.4375 mm. The closest standard hub centric ring is 71.5mm. So it appears the 78mm OD - 71.5mm ID hub centric rings might work. (also available online at Summit)
I forgot to mention that my '68 Barracuda Fastback has been converted to the large bolt pattern using '76 Duster discs on the front with '76 duster front hubs and a '68 Mopar 8 3/4 rear axle. However I'm still dealing with Mopar standard hubs.
3.) Yes, hub centric rings are required so the wheels stay centered since the wheels are neither lug centric nor center bore centric and there is a difference in the hub and wheel center bore diameters. This is probably why the previous owner sold them - My guess is that he tried to use them on his Dodge Charger without hub centric rings and was encountering wheel vibration problems because of the wheels moving off center (evidence: large and multiple lead weights still adhered to wheels) which prompted him, as he told me, to stack them in his garage for 20 years, not use them and finally sell them. The combination of hub centric rings and the correct lug nuts "should" keep the wheels centered.

Finally, anybody have good advice on short cuts on how to clean mag wheels? These are really dirty outside and inside. I know I can get them done by washing them in solvent then using a brass wire wheel on a drill or handheld grinder and Mothers Mag & Aluminum polish to get the hardened crud off followed by successively finer and finer uses of fine sandpaper and a final polish with more Mother's to bring the wheels up to a chrome like shine, but maybe there's a faster method?

Mopar On!

 

[lurchs66cuda]

I use the etching wheel cleaner and it works great. I pre rinse and then spray down the rim evenly with cleaner, then use brush or small rag to spread the cleaner around for about 2 minutes. It won't do much the first time so rinse and do it again. You'll notice the second application turns white and foams up better and will bring out the look of clean aluminum. Just be sure to rinse thoroughly and wipe dry or else water lines might form that are hard to remove. Don't leave the foam unattended once applied or it will also create nasty appearance.

 

[KOZ45]

Bumping this up

I just bought two SBP Shelby 500 aluminum slot wheels

Did you find rings that fit?

I am also looking for center caps if anyone has two