96 transport BASIC ENGINE REBUILD FRUSTRATIONS!!!

The problems started with it being a friends 96 Pontiac trans sport with 112K miles on it. One day it just died and wouldn't start, check the basic items (plugs,wires,air filter,radiator fluid,oil,ETC.) needed all new everything, noticed there was no radiator fluid in resivoir and upon draining oil it just kept pouring and pouring and after letting it settle lo and behold the GM dex cool was mixed in the oil (I had been told this stuff corrodes gaskets and engine parts, and that there was a class action lawsuit involved) so I replaced the head gaskets,plugs,wires,fuel filter,tps,OIL PUMP,thermostat,pcv, and so on, and after all this it starts but it sounds like its knocking a little loud, and the low oil light is on but the pressure is reading high, the engine light is on but not providing codes. is there something I may have overlooked? any help no matter how mundane would be greatly appreceiated.

Well you only did half the job!

If the coolant has been mixing with the oil for any length of time there is some definate bearing damage.
The knocking noise is a good indication of that.

Did you check the oil pressure with a manual gage?

(I had been told this stuff corrodes gaskets and engine parts, and that there was a class action lawsuit involved)Both are more urban myths then actual reality. Dex-cool doesn't corrode gaskets. The gaskets fail on their own. Dex-cool is just the scape goat owners put the blame on for faulty engineering. As to the lawsuit, there have been several filed and probably several in the works, but I am unaware of any lawsuits that actually went anywhere that were productive in any way.

If I read you well, the '96 you have is a 3.4 and this is basically an enlarged 3.1. I cannot be sure for the 3.4, but the 3.1 of former years used a fake oil pressure meter that would just indicate presence or absence of pressure through a fixed resistance circuit and pressure switch (while the 3.8 used a true proportional pressure sender). That might explain the light is lit but pressure needle shows OK if they do not trig at exactly same pressure...but this would mean there are 2 pressure switches...although I do not see that on my '93 diagrams..