Well, I didn't really think about this until recently....I dynoed a couple weeks back with good numbers:
253 HP/298 TQ
on my stock 96 Z

....my air/fuel was quite rich in the 11's...

Is this good? If not, is there anything I can do to alter it?

 

It does seem a little overly rich for a stock NA setup. You could probably lean the motor out to ~12.8:1 and gain another 10-15 hp. You would need either LT1 edit or Tunercat to do it. Just be careful if you attempt it though.