This page has a very good explanation of wheel codes and dates: CRG wheels
Example of the date codes I was looking for:
K1y m (hole) dd aa
where:
K = Kelsey-Hayes
1 = Romulus, MI wheel plant
y = calendar year
m = month
dd = day
aa = application code
K18 12 (hole) 17 YH = Kelsey-Hayes MI, built in 1968 in December on the 17th day with a YH code.
The car is a 1969 01B which means it was made the 2nd week of January 1969. The rally wheels that were on the car when I bought it have FW codes on them. Made around 1975 and definitely not correct.
According to the CRG
Rally Disc AD 15×7 Z28 (early)
Rally Disc YH 15×7 Z28 (late)
Being a 2nd week of January car, my car is a mid-production build. YH wheel production started in the middle of December 1968. There are only two 1968 date codes that would work, either 12-17 or 12-18 . Before this date, the wheels would have AD code wheels. Since these early YH dates would be perfect, I put an ad on the Team Camaro website that I was looking for wheels. THANKS for this recommendation Jeff68!
It didnt take long before I got a few responses to the ad and one guy in Wisconsin had 5 for sale all with the same date. They were not in perfect condition but could be fixed. One had more extensive damage but could be fixed and used as the spare.
The seller sent me this email
1st wheel
2nd wheel
3rd wheel
4th wheel