XG code rallys from 1966?

[KevinW]

So I picked up 4 XG rallys for my 69 to convert to discs.  I saw the 1966 date and figured they were for a 67 Camaro.  But just had a chance to look at the CRG page and 67 used a different code.  Now I am confused.  All 4 wheels are date 6/19/1966.  Were XGs used on another car? thanks

[169INDY]

My thought would be Measure the width of the Slot. I might have this worong, When did the Service Wheel slots go narrower from 1-1/8" to 1"
? could be 1970

Could it even be possible they got the 6 & 9 mixed up and this is merely a 1968 Service XG 14 x 6 Disc Brake wheel.

I can only find XC for 66/67 and that is 5inch wide wheel

additional dating can be found on the barrel.

[KevinW]

Thanks! You are correct, 1" slots.  So Service wheels, probably 1976 based on the surface pits.  I had forgotten original rim stamps are read from outside, service rims are read from inside.  Mystery solved. I am good with service rims 

[169INDY]

I had forgotten original rim stamps are read from outside, service rims are read from inside.  Mystery solved. I am good with service rims 

Maybe in General terms, but this is not a fast and hard rule:

Take my Early "DF" 15 x 6 Z28 rims are factory and are read from the inside. I am sure there are other exceptions to this. Same photos