true cam timing has to do with compression limitations.so does rod to stroke as well as air inlet temps,and how used(heavy pulling truck at low rpms and stabbing the throttle is an example of this)
the larger the cubes the less room to play with example a 396 will tolerate maybe 11 to one where as a 632 might only be 10:1....its all about cylinder pressure which i think someone might chime in for idont know max cylinder pressure u can safely get away with...
what is your combo and application?