Hello Ron,
You would have to be careful if you do a performance grind on the camshaft. These camshafts are "case hardened" from the factory. If they are simply reground, without being hardened, they do not last. As far as the head, raising the compression could require very high octane fuel not readily available in the US.
Performance upgrades like porting and polishing the head, extrude honeing the intake manifold, making sure you have the best factory camshaft and possibly re-metering the injection pump for max power, would give you better performance and not hurt the durability.
Pete Lesler and Frank Cozza have both competed in their 280SLs and probably have a lot of tips.
Joe Alexander
Blacklick, Ohio