Dodge Repair Questions? Ask a Mechanic for Answers ASAP
on the 4.7 and its sister the 3.7 the oil pressure is created via the MAIN bearings if coolant was getting into a cylinder chances are it got into the oil, oil into the coolant will wipe out the bearings pretty quick, since you said there was wear on the rod bearings (the LAST THING to get oil) the mains are very likely worn too.
this engine uses a split block design that actually splits the lower half of the block and casts the main caps into it so you almost NEVER get a main bearing knock with this design.
the only correct fix is pull the engine and replace the main bearings and even then this MAY NOT bring the oil pressure up to the 15 to 20 psi it normally has at idle, the clearances on bearing to crank are VERY tight in the order of .0015" to .0025" which is far tighter than any older engine