Wow Stephen.....Calm down buddy. I was'nt trying to set you off.
I know how it is to be where you are right now...hell I've been there myself, although I was much younger then.
Properly building an engine takes time and is realy alot of work.
You really cant approach it from the standpoint that "Well i bought new parts and bolted them together and its supposed to work"
There is much much more to it than that.
If you want to be successful at it every single part in the engine must be gone over with a fine toothed comb, old parts as well as NEW. If I had a dollar evertime I got a new part that was defective,mislabeled,misrepresented or just out and out the wrong part I would have a nice pile of cash.
While you may think the bearing clearances are right you really cant say they are because you did not measure them.
A small difference in bearing size( a difference you cannot see with your eyes) can make or break oil pressures.
When I first started rebuilding SC motors I too entertained the idea of oil pump rebuilding, infact I still have that unused rebuild kit.
After setting down and analyzing it I came to the conclusion that it really was'nt a good idea, and this is why I feel that way.
The 2 highest wear items in the system DO NOT get replaced.
The timing cover gets scuffed up by the spinning gears. The housing that the gears drop into also gets scuffed, this is important because those scuffed places reduce the amount of pressure the pump can make. The regulator bore in the timing cover also wears into an egg shape and is no longer round, so you get leakage of pressure there as well.
If you combine sloppy fitting bearings with a bad pump and timing cover that very well could be your problem.
I know you cant tell anyone what your bearing clearances are because you indicated that you did not measure them. Now dont take this the wrong way because I dont mean to hammer you about it but your inability to answer a simple engine building 101 qeustion is going to make it darn near impossable for anyone over the internet to diagnose.
You have a very serious problem on your hands and times like this really bother me
because I'd like nothing more than to get in the truck and head over to your house and help you fix this, but I cant.
The only thing I can say at this point is that if that was my engine I would pull it back out and tear the bottom end back down and measure everything.
Any 1 of these things or a combo of them can cause your problem.
1. Timing cover and oil pump not up to spec.
2. Rod bearing clearances not up to spec.
3. Main bearing clearances not up to spec.
4. Oil feed holes inside the block stopped up.
5. I have even seen oil filters shut off oil pressure before. Now before everybody flogs me and says "Well the bypass valve will still allow oil to be pumped through the engine" Yes I agree its supposed to but I've seen cases on engines when it did not and oil pressure was shut completely down to the engine.
#5 is a freak accurance and I would not hold my breath thinking that was my problem.
With your oil pressure as low as it is I do not recomend starting the engine anymore because youre gonna end up ruining good parts that you may not have to replace right now.
I feel really bad for you at the moment and wish I could be more help to you, but theres not really much I can do.