Just mounted my HRE 16 inch rims and 215 55 W16 Kuhmo tires on my 69 300 SEL 6.3. The standard lug bolts Part number 126 401 0670 that have an overall length is 2 inches were used on the front. I have Becker HubCentric 10 mm spacers on the rear to clear the ATE 42mm Calipers. I used Part Number 124 400 0170 that are 2 9/16 inches (including the head). Bought all the lug bolts from Mercedes Used Parts (michaelm@rainbowcostarica.com ). The Max tires I now feel you can stuff in the 6.3 is a 215 55 16 tire. It looks like a 225 50/55/ 16 is just too big. It would probably rub the shock or the fender lip. Just maybe some 225 tires might work, but it wasn't worth the potential disaster to try.

I am really happy with the Kuhmo Ecsta Supra 712 tire, it's W rated to 168 mph, has a capacity rating of 93 (1433 lbs/wheel) and 215/55WR16 93W 280 AA A 8.9" section width, 25.2" diameter, 822 rev/mile, and was only $75 at the Tire rack. Others in this size range include: Pirelli P6000, Dunlop SP Sport 9000, Michelin XGT V4, Michelin Energy MXV4 Plus, all with a V or higher rating.
Thanks again to Luke at TireRack!


Glad I went to 215 instead of 225 tires, there is less than 1/2 inch between the tire and shocks, and 1/2 inch between the tire and wheel well metal when the are bags are down some. The car feels GREAT now, what a difference!!! This tire combination is what Erich Waxenberger would have used if available back then.

My car pics are at http://members.tripod.com/~breastroker/MB_M100_16Wheels.html