On larger steep lobed cams it is common to preload the lifters more to keep the clack down or absent. Figure the target of HD is half way in the lifter is .100 of .200 travel. With heat the cylinders grow as much as .030 so changes to .070 to the top side, should this make a difference on piston position in the bore that can cause noise, it shouldn't. Take a look at a piston caliper, it has a tendacy to be less efficient when the pads are worn and caliper requires more fluid to fill the bore so maybe the extra lifter piston travel can relate to a caliper in recovery from open a valve.

Just in theory, when a Evo gets some worn items and it's low oil pressure is lower, oiling in the lifter isn't as strong plus longer recovery in the lifter bore from the piston higher in the bore from growing cylinders cause alot of the Evo noise, maybe, maybe not. I have always ran strong oil pumps, different lifters with HD B's being the weakest, lifter preload set deep (.150) with nasty cams and spring pressure, valve train have always been quiet. Current 640 lift cam is quiet at idle thru rev limiter and undetectable with a ear stuck on the engine.

Have always tried to have reasons why mechanical items work or don't work, many didn't work from mistakes as we all do but putting out some babble on the ticking Evo, just stuff in my head

 

the space that's around the lifter top and bottom is there for a reason. once full of oil, the pressure is the same at start up. point it either way and get the same result. that's my opinion anyways. no point looking for a problem on that assumption.

 

One thing that no one has mention about rocker noise is that I have seen wear in the pushrod end at the rocker creating a poor fit. I had a set of Revtech adjustables and no matter what I did I could not adjust out the noise. After close inspection I found wear rings around the ball. Replaced them and problem solved....

 

He might be on to something here. When you replaced the lifters did the pushrods go back in their original positions in the same direction they came out? Pushrods tend to wear into the seats on the rocker arms and if one got spun end for end that could cause a little noise.