I have a 1977 440, freshened up with new rings, rod bearings, main bearings, cam bearings, cam, lifters, timing chain, etc...
It has roughly 3-4000 miles on it now, cold oil pressure with 10w30 bit almost 80, runs down the road warm at 60-70,
Now all of a sudden it has developed a knock under load over 2000 rpm, oil pressure never changes and stays good, checked torque converter bolts, flex plate for crack, exhaust, everything is in order, it will not make any noise in park of neutral up to 4000 rpm, any help of advice greatly appreciated.