I have a 67 with a 454...The engine has an 8 quart oil pan with a Melling hi-flow oil pump. The engine has approximately 2500 miles on a complete new build. When I start the car cold, it generates 70 to 80 psi oil pressure. As it warms, it drops to between 40 and 45 psi. When the engine is fully warmed up and operating temp, it cruises at highway speeds and maintains 40 psi..at an idle, it drops to about 10 psi. Makes me nervous. $$$$ Is this normal and common with big blocks? A buddy of mine told me that big blocks are known for this. True?