OK i have most of the bugs worked out but i still think it is going to be a shakedown summer. I am running a melling HV pump and a 16 qt pan. I set the mains at .003 and the rods at .0028 + or - .0001 or .0002 and i am a little concerned about the oil pressure i am running. i am running a 540 with 9.7:1 with afr alum heads. i have decent oil pressure when i am cruising. When it is cold (60lbs) or just up to temp i am running about 20 lbs idle . I did put the the higher pressure relief spring the pad and i originally used Havoline 10-40 non synthetic oil for the break in period on the engine. When i run it kinda hard for about 10 min or so the pressure drops down to 10lbs or less at idle some times bouncing off of 0. I know my cooler is a little on the small side (any one have a bigger one i can buy) So i switched to 20/50 on the oil.. I still have the same #'s/problem? Am i missing something major here? Do i need to pull the motor and tighten up the clearances? I do not want to fry the crank and even worse the valve train. My pressure sender is right in the pad by the remote filter adapter. I put a 2nd mechanical one in the upper back passage in the block just as a verification that my original one was calibrated correctly. My oil cooler is only about 8/10 inches long and it runs power steering through it also. Any suggestions here?