[Mike Taylor 3601]

Wasn't first version 492 with angle plugs and still had heat risers?
then second was 292,had heat risers deleted and raised the angle plugs higher in chambers?
First thing to watch out for is spring seats,have to cut pocket OD with shim in place or likely will hit water or soon after crack there,don't cut to match original depth.
292 was prone to crack in intake runners probably had to do with amount of porting done that has been done.
Mike Taylor 3601