Shoot I have a Melling pump I got new and it never made more than 60 psi or so, pretty rock-solid but definitely never anywhere near 72-75 psi. Maybe I got an MP one off Mancini? It was 9 years ago I can't remember lol, I do remember it was a standard one though not HV or HP.
You got the lower pressure relief spring.... 55 psi. The 2 springs look identical but if you put a caliper on them you will find the spring wire in the higher pressure spring is a few thousandths thicker.
