You can run pretty fast with a 264-268 @ .050" cam. Going to a 272-284 cam @ .050" can require higher quality/ stiffer springs and more required valve train maintenance.
The stiffer the valve springs the more frequent valve spring changes are a possibility. The faster you go the more it cost initially and upkeep cost.
Years ago I raced a car that ran 7.50's in the 1/8 mile, which back then Super Pro was 7.99 or faster. There was a dragster that ran 4.51 @ 151 mph in the 1/8 racing at my track every
week. I had a nice roll cage, but was my car safe enough to be on the track if I had to line up next to this guy?
All that said, if you race in a class were you are lined up and racing a much faster car than you, aka: Super Pro your car should be safe enough to take a hit in the rearend from
that faster car racing towards you in the lights at 150 mph should something go wrong with either car. The short answer is I would have in no way been prepared safety wise should have
something ever happened. I don't know you or your car, but before I worried about going faster I would make sure you're as safe you can be before going faster.
Tom
