According to the exploded views of the Flash 12-3 Tuned and Flash 12-PT, the 12-3 Tuned P/S set is 08627/10 and the 12-PT is 08627/11 (only ONE number!!), so perhaps there is a slight change in port shape or timing making them different, and the cranks are different to each other according to the part numbers.

Maybe it was the RB Touring .12 engines I was comparing that had the same cranks and P/S sets, pretty sure that's what I was referring to in my previous post