The only specifications I could find are that the oil pressure should be 40-60 PSI at 2000 RPM.

I think a good leak down test/compression test would be a good idea. You may have some wear on the rings. Do you have a compression gauge that you can test with? Many auto stores have loaner units if not.

 

yea i have a compression gauge. ill have to check it out and get back to ya with the results.

 

so here is the result of the compression test.
Cyl 1- 75psi
Cyl 2- 85psi
Cyl 3- 75psi
Cyl 4- 75psi
Cyl 5- 80psi
Cyl 6- 70psi
Cyl 7- 65psi
Cyl 8- 75psi

 

I'm not near my manuals so I can't check anything other than forums. What I've read so far is that compression should be anywhere from 210psi-120psi.
The figures you list above sound quite low.
Can you re-check again, and make sure to crank the motor 5 times, and confirm the values? After you've rechecked a cylinder, pour a tablespoon of oil into the chamber and see if it gets higher.

 

so i rechecked the compression again. and still came up with the exact same numbers. i added a tablespoon of oil to each cylinder and still came up with the same numbers.

 

Condolences.

 

Go to NAP and buy the best filter for your truck that they have. The NAP brand is made by Wix, and they have a pretty good filter. at least that is what I have heard. Change the oil. 3 qrts of 5-W30 " High Mialage Oil" . 3 Qrts of High end oil. ( a little thicker, 10W40 Lucas, or other syn 1/2). Only add 5 qts at the oil change in total. Keep the 6th qt as reserve. Check the Dip Stick after oil change,but before you start the engine . If it reads 1 qt low after oil change, then add 1/2 qt. Take it for a 10 minute test ride. Park it on flat ground, wait 10 minutes,and check the oil level with the dip stick. If low add the six'th qt, or till full.(no More than Six) Run it through its regular drive cycle, and see if iit pulls blue/white smoke again. And when you say " ALL HELL BREAKS LOOSE" @ 2500-3000 What do you, or others See, Hear or Smell? What breaks loose? Change the oil & filter. Or its not ventilating right. Thats where I would start. (BWDIKnow)

 

currently running brand new Royal Purple 10w40 and napa filter. i noticed today that my oil pan is leaking around the gasket on the starter side. gasket is not seated properly. could it be pushing oil out of the pan and running on the exhaust making it look like its smoking?

 

No, oil pressure should be around 30 psi, If you are really getting 7 psi, stop driving and find the solution.

Time for replacement engine, or rebuild. Bearings worn out or valves leaking beyond tolerance.

 

1990 Service Manual has the hot oil pressure at 40-65 psi at 2000 rpm.

You're about half that, bearings are bad.

 

Where did you hook up the mechanical oil pressure guage?

 

i hooked up the mechanical gauge up where the factory sender was. cause my sender went bad. it was broke off

 

is there another place to hook it up?

 

Well, if the oil pressure is actually that low, and you're not having some other issues, I would suspect that there's some kink or obstruction in the oil pressure line.

 

i installed a copper line in the truck to make sure its not kinked and its not at all. i doubled checked. i was under the truck today to check my trans fluid and noticed the oil pan gasket is sorta out of whack. about 2 inches of it is hanging out of the pan. and everything from the starter down is covered in oil. could it just be oil running from the pan onto the hot exhaust making it smoke?