3406C Pete 379 1995 Dies at 1800 RPM's

Were drops of hard gasket glue on your oil pump screen? a tube of gasket maker put on oil pan before bolting it on will let what gets on inside of pan go into oil screen an make oil press drop when eng is hot?

 

It sounds like it still has air in the system or the lines from the new transfer pump are not sealed or the transfer pump itself is failing.

 

What about fuel system restriction? Plugged fuel tank vent?

 

The B plungers wont push the higher cracking pressure of C injectors long.

The C pump uses dual scroll plungers. My advice is put the C pump back on it ASAP

 

Get that Lucas #### outta there
Pure garbage! It's a 60wt oil with viscosity index improvers (thickening) ..

.. It has ZERO anti wear additives .... It literally dilutes good oil... Baaadddd!!

Lucas also creates a huge oil aeration problem... Displacing oil with air bubbles... Again, BAD !!

 

approximately 50 pounds when warm is a decent pressure. Dude who says 20 to 25 is on drugs. He runs an old worn out cummins.
80 PSI is high although the sender could be screwed up or the pressure regulator needs looking at. You need to take this to a truck shop and have it fixed. This diagnosing over the internet really brings out the IDIOTS.

 

I think you still have some fuel issues. Take the truck back and tell the people who repaired it to fix it.