I did a lot of research on compressors and talked to a local repair guy, he pointed me to Champion brand and they are very durable.
The valves can be accessed from outside and are spring loaded disc valves, rather than reed valves attached to the underside of the head.
The Champion compressor has no removeable head, the valves are under screw in caps on the top.
Quote from my repair guy:
"When a reed valve compressor is run too long, (like contiuous use, with a big sand blasting job) the reed valves can overheat and fail where they hinge then break off, fall into the cylinder. The cyl head gasket also get's cooked into the head and getting it off is sometimes very difficult."
A smaller motor can sometimes run a larger pump, you have to gear it down though, and will get less air flow.
Check my web page for First Gen Camaro suspension info:
David's Motorsports page
First Gen Suspension Page
67 RS 327 original owner. 69 Camaro Vintage Racer, 65 Lola T-70 Chev SB Can-Am Vintage Racer