Last month I posted a problem with my 1988 765T. The oil pressure would DROP the HIGHER the RPMs. After two oil pumps and trying to clean out oil passageways, I chose to try another block. Now with the same oil pump, shaft, rods, pistons and head I have a fine running car.

Here is what I found in the old block. There were some loose pieces of metal, (non-magnetic) sort of floating in the oil passageway that feed the bearings etc. on the “clean” side of the oil filter and cooler. My theory is that they would gather at various locations in that passageway and dam up the oil. I cannot figure out how they got there (the largest piece was about the size of a pencil eraser but flat). This was an engine that had been severely overheated before I got it. So… the problem is solved but I don’t have the confidence to use this old block again.

Thanks for everyone’s ideas.
Jon