Post a pic of how the engine looks under the valve cover before cleaning

 

OK when I open up the drives side I'll post a picture.

In the mean time I did some research in rave o

n the components of the lifters and how I can take them apart clean them and put them back together. I also found a video of a nice guy rebuilding a very similar engine and putting lifters in it.

 

Found the intake manifold gasket and seals for a good price would it be worth it to remove the intake manifold to try to clean the lifters.

 

replace the gasket for other good reasons.....proactively avoiding a leak there ( either coolant, air , or oil )
"cleaning" the lifters can be a roll of the dice....you may so SOME good, but could also release some crap that might make it worse.....as said before >>remove and clean (or replace ) the rockershaft assys...these things are somewhat prone to having a rocker arm insert loosen up as the engine warms up and then starts ticking....I was only able to pinpoint a tick I had on my 98 by removing the valve covers, starting the motor and let it warm up..easier to see where the noise is coming from....not to fear,you wont cause much oil mess at all

 

You asked in previous post about disassembling lifters to clean them?

Most folks replace with new lifters since relatively inexpensive and they may be worn. If you attempt this take them apart to clean in a plastic bag so you don't lose the small parts.
......

 

Oh I should have tested it with the valve cover off like you did. I might do that. OK so still not sure weather to clean lifters because like you said it's a hit or a miss. But I will definiaty clean rocker assemblies. Now how do i know if it has a loose insert and does the rocker shaft need to he replaced to fix a loose insert?

 

the rocker shaft "assy" can come apart... cotter pins, springs and washers...easy job..clean out all the baked on oil gunk, clear out the oil passages.....if you havent taken them apart yet....run it till it's warm with the covers off and the noisy one(s) will be easier to spot. the rocker arms are aluminum with steel inserts where the push rod contacts them, and steel inserts where the rocker touches the valve....the aluminum can expand and the steel insert will actually be loose in the rocker arm and "tick" or rattle as the engine warms up.......before you disassemble the shaft assys it would be nice to know which ones are bad.....if its only a few you can replace them, or might be cheaper to do the whole shaft assy....but at that point you will have narrowed it down....I had 4 bad on my 98 at one point, what a symphony THAT was lol
with good oil, the lifters will take care of themselves, unless they are beat beyond help......and in that case so would the cam be

 

Oh now I see what you mean about ticket arm inserts. Very well could be a possibility in my case. But anyway I removed the driver side valve cover and here's what I found...

 

 

The pic looking into your rocker shaft pedestal is indicative of what and why you need to take the entire assembly apart to clean it. That was sitting on top of the head, imagine what's inside the shaft where the bolts run through it. More carbon. Carbon not only blocks off flow it's a beyotch to get off with common solvents. Clean the outside as best as you can then remove the rockers from the shaft one by one and place parts in order as removed so you can turn and burn em back on like they came off.