A lot of scratch for a SOHC, if you want to keep your stock motor, might be worth considering. Who did the head work and does he have reciepts. It should run strong but might need more than a beefed up head. Did he give you any dyno charts or timeslips for his car. Only other thing I recommend is find an EX tranny (short, more aggressive gear ratios) and consider maybe getting some internal engine upgrades (higher compression pistons). Probably going to end up spending as much a B16A2 swap (motor out of the '99+ Si's) will cost you though, for about the same HP. Seeya.