Oil pressure problem

[737dezertking]

Need help I have a 4.0 manual with a rebuilt motor with 48000 miles on it and I heard valve tapping so I changed the rockers and they were worn out. I put in a manual oil pressur gauge and only got 6 psi at idle hot and 25 at 2000 rpm.cold start 40 psi at idle and when warmed up it would drop slowly.im running a 160 thermastat. So I pulled the motor for the 6 time and installed the melling328 highflow oil pump. Meanwhile I checked the crank bearings and the thrust bearing was completely worn out only after 48000 miles but I mash on the truck out in the desert anyway so that dosent help. I could push the crank back and forth 1/64 of a inch so I replaced all crank bearings and also did the rod bearings. Put the engine back in and now at 2000 rpm hot I'm at 35 psi and 900 rpm it verys from20 to 10 psi at idle.cold start at idle is 54 psi and when I rev it up it dosent increase pressure very much. What the hell is going on help please