I've tried to stay out of this, because wheels, can get very difficult, & confusing. There were many different 20, & 22.5 inch wheels available for these G.M. Big bolts. For example: There were 3 piece, 20 X 5.0, 10 lug wheels, with 5 hand holes, & there were 2 piece, 20 X 5.0, wheels, with 8 hand holes. 20 X 6.0, 3 piece, 10 lug, 5 HH, & 20 X 6.0, 2 piece, 10 lug, 5 HH wheels. There was indeed a 2 piece, 10 lug, 20 X 6.0, 5 HH(GM prt. no. 2395276)wheel available, as far as 1970, from what I can tell. There was also a 2 piece, 6 lug, 20 X 6.5 wheel, 6HH(GM prt. no. 2395848)available, from 1960, at least to 1970. Daytons were first available on Heavy Duty Chevy Trucks, in 1957, but were available on Heavy Duty GMC's, as far back as the 1930's
