292/508 question

Aj has it right in post 33 and just above
advancing screws up your power stroke opening the exhaust too early and opens the intake too early diluting your mixture with exhaust gass, exhaust closing too early hurts scavenge
just figure out where you want your valve events IO IC EO EC and get a cam ground accordingly--
overlap and LCA should be a result not an input
run a larger pulley on the AC Compressor and a high speed (or full throttle) cut out
1969383S has it right - bracket racing cam and way obsolete
you can get more duration at 200 from a modern 270