Is my engine performing as it should??
if you are staying with the stock converter and gears I would not use the .508 cam....
that cam has alot of duration and will kill you bottom end torque.
I wouldn't do the 508 either.
A 484 will, 95% of the time, outperform a 508 cam except for the last 5-800 of usable band. With the carb you have the top end is going to suffer, so the 508 is a mismatch. I think you have some mismatched stuff.
If you are going to run stock rockers, stay with the 484 or a XE268H cam or something similar as the max lift range. Putting 1.7 rockers on this is an absolute waste of money, IMO. Try to find a flowsheet for the heads if done by a shop, without it, camming it is a guess at best. Plus, what they flow at .600 lift means nothing to you because the cam you are running is only accessing about .400-.420 lift ranges.
IMO, figure out what you want out of the engine. There are plenty of solid 350-400 hp builds for a 360. The current compression may be a bit of a hinderance, but, you can work around it with smart parts selection.