compression is ok,,,,,lifters ok......runs fine....lately my oil pressure has dropped dramatically when temp rises..im talkin 15/20 =holdinglbs....this is scary..gauges seem to work ok..could this be my oil pump surging?i don't wanna blow a lethal small block up..stumped..cured the smoking..we got timing straight..replaced plugs.....any comments ok?could i have a crank problem?