might be the cam, how many miles on it?

250k miles, If it'* the cam wouldn't it always make the noise? How would i check it without pulling it out?

After replace them, are they loose again? I suspect you have one stud that'* pulling out and create the ticker

also, dump a quart of rislone oil treatment in with the oil.. if that helps then oil is restricted and or lifters wore out

your initial condition was a bunch of the rockers loose. only way that can happen is worn or bent pushrods, bad lifters or bad oil pressure to them(oil passages blocked) or the cam is worn down enough the lifters cant take up the slack. the more oil pressure you say(higher rpm) the bigger the lifters get and take up the slack in the system. the cam is difficult to inspect, all you could really do is take out the lifters and look in the hole and see if there are any obvious scratches. inspect the other components as well first

its tough to figure out sometimes. i had a tick in mine when i got it but it ended up being the intake manifold gaskets were letting coolant in the oil and thinning it. nothing looked white. when i changed the gaskets and put a little seafoam in the oil and changed it again its mostly cleared up. only a few seconds when cold

I started to think around this way too, I am replacing all the lifters when it stops raining . I wanted to avoid pulling the intake because it is a lot more to remove and with 250k miles i am sure i have to replace a ton of gasket seals also . Unfortunately after i pulled a valve cover to check it does not seem to be an option to pull the lifter out without pulling the intake off , in thus here comes hours of added pain .

sorry forgot that one does use a lifter retainer. the fortunate thing is the lower intake gaskets suck and probably needed done anyway. they make a kit that has all the gaskets for the job

4.3L, 5.0L, 5.7L And 7.4L Engines

Remove the cylinder head cover.

Remove the intake manifold.

Back off the rocker arm adjusting nuts and remove the pushrods. Keep them in order for installation.

Remove the lifter retainer bolts, retainer and restrictor.

Remove the lifters. If your are going to re-use the lifters, remove them one at a time and mark each one for installation. They must be re-installed in the same locations. If a lifter is stuck, it can be removed with a grasping-type lifter tool, available from most auto parts stores.

Inspect each lifter thoroughly. If any of them shows any signs of wear, heat bluing or damage, replace the whole set.

Coat each lifter with engine oil supplement prior to installation. Tighten the retainer bolts to 12 ft. lbs. (16 Nm). Adjust the valves as described in the valve lash procedure.

After about a week of rain I got back to the truck engine . The intake was taken off to find the inside is pitch black , I assume the last owner did not change the oil like they should have . Following a few minutes spent scraping out chunks of coagulated oil the lifters were removed ,taken apart, and cleaned from the inside out . During disassembly I noticed a few of the lifters would not compress . Inside of the lifters there was the same coagulated oil build up from the lifter valley , a little bit of chemtool b-12 with a rag cleaned all the parts to a shine. Once cleaned the lifters now all compress fine, is there anything else i should check other than the gaskets before i close this thing back up?

i dont know what you do about it on a v-6 because i dont have one but ive heard the dist base is not adjustable so if you get a 1345 code the dist is not right. on a 8cyl you can just move it so it good enough to take it to a shop to have the cam retard offset checked. unless you have a high end scanner that does it. i took it to a shop that only wanted 25

Engine is still ticking , the noise is either a little lower or i am forcing myself to think that after all that work i have done to it . Anyone have any clues ?