the HS rockers for a BB are a tad long when used on OE or Edelbrock heads.
still usable, but not the ideal contact pattern.

however, they fit the Indy heads quite nicely.
basically perfect roller placement and plenty of spring/retainer clearance.

the ICH rockers seem to be split the difference in the length between the shaft centerline and the roller tip centerline compared to the longer HS rockers, and the noticably shorter Crane and Comp rockers.

attached is a HS rocker on an Indy head.