if those HV pumps are maintaining that much pressure with the relief open they should change things a little bit. that said i used to be of the opinion that the bigger the oil pump the better. now that i've grown up (somewhat) imho the best oil pump is the smallest one that will maintain the desired pressure. imho i wouldn't install any pump before taking it apart and looking it over. too much chance for metal scrap or what not to be in it.