what are the fundamentle differences in lp and hp and which is better and why also what is better for a pm7 just would like to know the difference as i tried doing a search but no luck lol thanks
Output pressure is the only different. LP is in the 450 psi range, HP is in the 850 psi range. On your PM7, either one will work fine because your inline reg will reduce either one to a much lower pressure.