A buddy of mine is getting ready to fire the 427 bbc in his flat bottom and when he runs the pump with a drill he is getting 100 psi pressure at the gage. Is this going to cause a problem? He is using 20W 50 Valvoline Racing oil. The engine has been sitting for quite a while, is it possible the by pass in the pump is stuck, would that even cause this? It has the stock GM oil filter adapter .