Compression test is easy. Pick up a compression tester from Sears or some auto store. Very self explanitory. Bad compression usually can only be fixed through mechanical means like re-ringing a bottom end or reseating straight vlaves on a head. Too tight of a valve adjustment can cause a loss of compression too. A motor with really big cams causes alot of overlap and a loss of dynamic compression when when compression tested. This is th reason motors with big cams like a high static compression ratio......blah blah blah