340 lifter noise
should the lifters all drain out after sitting a while or stay full?why would they make noise? to much clearance some where? or junk in the lifters? tks
The only way that a lifter will drain out is if there is pressure on the plunger for a period of time. This could be caused by an open valve when the engine is off. The pressure from the open valve spring may make it bleed down. A lifter just sitting with no pressure on the plunger (valve closed) should not bleed down. In many cases if the lifter does bleed down, it will "pump itself back up" when you run the engine for a while.
The standard hydraulic lifter should not be affected by changing head gaskets for the standard stamped steel rockers and going from stock to Fel Pro thick gaskets. I have done it many times.
Do you have adjustable rocker arms or the standard stamped steel stock type?
Have you checked for an exhaust leak? If you pulled the heads, maybe you have a leak at the head/exhaust manifold or header flange face. It can sound just like a collapsed lifter. Put some dish soap mixed with water (Dawn/Palmolive liquid etc) into a spray bottle and spray it on the whole exhaust face where the heads and exhaust manifolds meet and run the engine and look for bubbles. That would indicate an exhaust leak.
You may have a loose or missing piece of your rocker gear, pull the valve cover and double check that all the rocker arms and any spacers are in the correct location.
Is it possible you may have gotten a piece of dirt stuck in one of the lifters when you took everything apart?
You have good oil pressure at 60 lbs. check to make sure that the rocker shafts are not installed upside down. There are oil holes on the bottom of the shaft. If the shaft is upside down, it will shut off/block the oil getting to the rocker arms. The side with the holes goes down, and the side without the holes goes up.
Also, could you have misinstalled the head gasket? there is an oil passage from the block to the head that feeds oil to the rocker arms. An upside down or backwards head gasket will block off that hole and not let oil get to the rockers?
Run the engine and use your longest screw driver with the tip down and put your ear to the handle (or close to it) and use it as a stethiscope. Try to isolate where the noise is coming from. See if you can pin it down to a particular cylinder and intake or exhaust lifter if possible.
Hopefully one of these will help you find the source of the noise. these things are the first to pop in my mind. Good luck.