Predicting dyno numbers is a difficult proposition. All dynos read differently and cannot be compared against each other. Even dynos of the same brand. First and foremost, the dyno is a testing and tuning tool that will show you gains and losses throughout the RPM range while comparing runs done on that same dyno, and guides a tuner by showing the results of the tuning. The gains from a baseline run are what is most important.
This is a sticky in this forum and a good read on dynos:
http://www.ft86club.com/forums/showthread.php?t=20572
So, back to the whp question. Our stage 2 tune with full exhaust including headers will net a 20+ whp gain over stock, plus greatly improved torque, eliminating the torque dip. The realistic range on the above dyno is 195 - 205whp. An aggressive 93 octane tune done on the dyno could possibly reach the 210whp range (that's an assumption), but the highest stage 2 tunes we have seen are topping out right around 200whp.