Doug is correct. I too worked at Goodyear mid 70's. ET's had a plastic insert that went in the back of the rim to select bolt pattern and washers on front. It was a 1 piece circle. Cheap design. We had a drawer all them because they would wear. I have a set for chevy 4.75 bolt pattern from a set of Ansen sprint 2. They used an egg shaped metal insert in the back of rim and a center or offset washer on the front. 1 was center for 4.75 then the other insert could be installed at 4.5 or 5.
Cragar used a die cast piece o the backside of some SS wheels. Also remember ET's having a reputation for loosening. never ran them so I can't say I experienced it but thought it was worth mentioning should anybody be running a set
at one time, i had a pair of 15x3 wide SS wheels that came with that ring for a 4 3/4" bolt pattern. i obtained a pair of 4 1/2" rings so i could use those wheels on whatever i put those at the time.
when i sold the wheels, the buyer wanted to put them on a GM, so i gave him the 4 3/4" rings, and kept the 4 1/2" rings.
i think i still have those rings on the shelf somewhere................
at the time, around here anyone running et's with the washers had to keep close attention to get and keep the washers positioned correctly on the wheel, especially when tightening them up. many wheels were ruined because the washers were not in the wheel pocket correctly, resulting in boogering up the wheel. and yes, the tapered et lugnuts did have a tendency to work loose at times. i always checked lugnut tightness often when running those wheel types. i never had much trouble with them working loose like some guys did, but i usually torqued them to 85 ftlbs.
