1969 Z28 Rims / Stamping ID letters...

[rpoz11]

Hi! Got a friend who is original owner on a 69 Z; Yellow/Black Std./Factory Chambered/Build sheet/all doc's., etc. We found today that the rims are stamped "AD", not "YH". The rims are definately different throughout, spacing, 5-holes are larger, inside bead lines are much more sharp and defined. Are these correct for his car? He has never changed the Rims on this car, EVER! He pulled out the original spare and it, too!, was an "AD" rim. Anybody's help, thoughts, or input is Greatly appreciated!! Thanx! [img]/ubbthreads/images/graemlins/beers.gif[/img]

[mssl72]

Digging into Alan Colvin's Chevy by the Numbers here is what I found:

AD- Camaro High Perf. Z28 15x7 JJ
YH- Camaro, replaces AD 15x7 JJ

"The AD wheel was used early in the model year. It did not have provision for the four-wheel disc option. According to Kelsey-Hayes documentation, the YH wheel was not released until 2/20/69. This has not been verified from original cars."

I guess from this information that the JL8 option helped the wheel redesign. I don't know what was been changed. Alan shows all the wheel dimensions as being identical. What's the build date on your friends car? It may fit in with what's been written by Alan.

[img]/ubbthreads/images/graemlins/beers.gif[/img]

[rpoz11]

I believe that it is an August/September 68 body run. I can post pics of the differences between the rims. They are Definately different throughout! He and his brother, of all things, both went down to the dealerships and bought brand new cars at the time, his being the 69 Z and his brother: purchased a 69 T/A!! Ill get with him and post some pics on the rims!! [img]/ubbthreads/images/graemlins/beers.gif[/img]

[William]

AD and YH wheels are not identical. The raised section formed into the rim that mounts the center is about 1/4" narrower on YH wheels. An AD wheel will fit a JL8 axle however the caliper is very close to the rim. The extra clearance on YH wheels allows for flex under load without contacting the caliper.

[mssl72]

That makes sense William. The dimensions in Alans book only reflect offset, bolt size/center and center hole.

rpoz11-Sounds like your friends car is an early one. Does he have JL8 on it too? Does his brother still have the TA?

[DarrenX33]

Interesting. My car has what I believe to be the original spare. It is a YH rim. Build date on my car is 02B. [img]/ubbthreads/images/graemlins/dunno.gif[/img]

[Z28DZ]

The earliest YH wheel I've observed was dated 12-18-68 and I have heard of late Nov. 68 dated YH's. My 02A LA Z has YH wheels dated Jan. 69.

[Kurt S]

Yup, 12/18/68 is the earliest YH wheel, though I might have seen a 12/17/68 one once.
Earlier ones will be AD's, very hard to find......