Noisy valve train, little oil thru pushrods

You may have seen my post in "Good oil pressure, but no oil!!"  I figured I should start a new thread of my own as not to steal his.  Also, you may have seen my "Cylinder head installation questions" thread.

Well, I installed my freshly rebuild heads.  The engine has a terrible valve train noise: clicking and tapping.  I am going to install self-locking rocker are nuts, but now I am thinking the problem may be something else (although I will still install the new nuts).  

If I run the engine without the valve covers there is very little oil seeping thru the pushrods, even when I rev the engine.  My oil pressure gauge reads about 40 psi upon start up, and after about 10 minutes of running the engine it drops to around 20 psi.  Is that normal when it warms up??  And why is there so little oil coming thru the push rods??  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Is the lifter preload set right?
Is the oilpump new? Also what oilpump is in the engine?  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Oh and how much oil pressure did you have before?  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

I didn't have an oil pressure gauge before, unfortunately.  I was wondering that myself.

The oil pump that's in it is the same one that has been in it since my Dad bought the car 16 years ago in California.  I have no idea what it is.

I just torqued the rocker nuts to 20 ft lbs.

I am going to install self locking rocker nuts and adjust them using the method you described to me on my other thread.  Is that what you're referring to when you say "lifter preload"?  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Yep!  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Okay cool, so that will take care of the noise.

The fact that oil doesn't shoot out of the pus rods when I rev it is okay, and normal?

And the oil pressure dropping to 20 once warmed up is okay too?  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

The oil not coming through the push rods can be from the valves not being set properly.

With out knowing what pump you have standard, hi-volume, or hi-pressure it is hard to tell.
How many miles does the engine have on it?  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

My 301 pontiac in my regal has a hi-pressure oil pump and it has 40lbs when hot and 60 when cold and has a 140,000 miles on it.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

I couldn't even tell you the mileage.  It has a '70 GTO 400 engine (not original), and the mileage reads 054,000 or something.  So who knows.

I am ordering those self locking nuts and a PerTronix ignition conversion kit.  I should be in pretty good shape after that.  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Okay, I adjusted the valves on the driver's side bank using my new self adjusting nuts. I made sure the valves were closed, tightened the rocker nut until all vertical play was gone, then tightened 1/4 turn more.         I started the engine, ran it for a while, and revved it up.  I saw pretty much no oil through the push rods, and the valve train is still noisy!  Any ideas?  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

I just adjusted the passenger's side too.  All the valves are adjusted, still no to very little oil through the push rods, even when revving the engine.  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

what is your oil pressure.
Also did you check to see if the push rods are clogged.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

I gave the push rods to the machine shop and they cleaned them.  They did come back pretty clean, so I doubt they are clogged.  The oil pressure is between 30 and 40 psi at idle.  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

did the engine make that ticking sound before the heads were rebuilt.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

No, it did not.  In fact it ran pretty well and quietly until it overheated and an exhaust valve got burned.  I don't know what the deal is.  I'm going to call the machine shop about this problem.  Also, my vacuum gauge rapidly vibrates at engine idle.  Perhaps the noise and the vibrating vacuum needle are related?  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.