i have a 2000 f-350 6-spd i just overhauled the engine about 3000 mile ago. I punched it .030 over and had the block and heads resurficed and put new pistons rings rist pins mains and rod bearings with stage one single shot injectors from full force. when i go to start it up it has like a fuel nock noice but as the engine warms up you do not here it that often but when u drive down the road it has a like a pulsing growling noice but it is not consistant. My first instink was im getting air in the fuel, but when i overhauled it i change all the o-rings on all the fuel lines. I had a couple of leaks and it still does it. The head gaskets that came with the rebuild kit blew pretty quick, but this time i went with a oem gasket and i checked the block and heads with a straight edge and they were fine. My engine oil pressure is fine when driving down the road and at idle but when i take off from a stop and lug the engine and just for a second or two the oil pressure will stop. I hope that somebody can help me!!!!!