This is for an engine dyno, or gross HP? Well, subtract 30% off what the engine dyno says and that's what is hitting the ground, or net hp. 100 crank HP is only 70 HP at the ground, which isn't much.

Gaining 1/5th cc and claiming 1/2 more hp (60+30) or nearly double ? Even with all the tricks,factory engineers German or Jap that season a motor and put the right size ports , valves, cam, balancing etc and us rednecks just call California and listen to all their verbage and throw unbalanced chineese stuff in a case and expect results that they can't match.I'd guess at 80-85. and that is over a 1/3 more hp from the original 60.)