Classic/Antique Car Repair: Master cylinder question..., chevy el camino, power brakes

Question
Mr. Warrington:
I've got to replace the master cylinder on a 1979 Chevy El Camino (350 engine)...but I don't know whether it's got power brakes or not.  Is there something I can look at that will tell me definitely one way or the other?
Any info/advice greatly appreciated.
Warm regards,
David Gardner
davidg32@yahoo.com

Answer
DAVID:
Hea-  Well if it has the big round air tank on top of the master. clyd. than it is air asst. if none than its reg. I would use some H.D. pads in it -but not metal and if you need new rotors get some h.d. also./ or /if not bad at least get them cut. and the seals  and calipers if any leaks - fix them