what size track and what type of racing your doing...the only reason I say size of track is cause I know most people are saying that the monster is High reving so you need a fairly fast track to keep the rpm's up...the P2K2 is a little more suited to both worlds......good torque and rpm
Monster is a little more rpm. I would gear it 8.0 -7.5. They have no bottom end but they'll spin like mad. I've seen a few dogs so maybe quality control has been asleep but the good ones were impressive.
P2K2 is a solid motor. Easy to tune. Haven't seen too many bad ones. And have seen some amazing ones.