Where do I find the date codes on my '77 Z28 wheels? I've looked on the wheel (the tires are off) and all I found was the 15x7 part. Where exactly are these date codes?

On the OUTSIDE of the wheel.....but UNDER where the trim ring would cover, NEXT to where the rubber air valve enters the wheel...I cant be more clear than that....Code starts with K (Kelsey Hayes Mfg) then a series of numbers.....send them to me or post here and somebody with decode them......Chuck