Removing air:
The best thing is to drill 1 or a few 1/8" holes in the flange of the thermostat itself, so that even when it's closed a little water can flow. Re-assemble, fill with water, and idle the engine until it's warmed up. As it pumps water, it will clear out any air bubbles. Add more water as needed.
(I don't usually put anit-freeze in the first time. Seems like you always wind up opening up the cooling system for one reason or another; why create the drainage hassle? Once everytingis good, drain and refill w/ antifreeze.)
As for the power level, rich mix = less HP. Likewise, if the timing is off you will lose power.
But overall, congratulations!
Cheers!
George
