Trying to identify lifters
 

I decided to tear down the big block chev engine I bought last spring and I am having trouble identifying the lifters. The only marks on the lifters is the number 502 scribed in the lifter body. The lifter OD is 0.904" and the outside diameter of the roller wheel is 0.808" (maybe 0.810"). They are a solid roller. Can anyone help me ID these lifters? Thanks.