I see now the comments, thank you. actually i did the break-in of the cam ( XE275XL Comp Cam) as instuctions ( of course I primered with electric drill before 1st startup) and yes it took a little while for the engine to get quite maybe even because of thick 20W-50 oil. The problem was starting the engine the day after, I got a diesel sound again because of 2-3 lifters totally bleeded . Then all this week I've been experienced the same problem and not with the same lifter position, I've been checking and trying more or minus preload until the decision ( a bad one) to install a new set of the same high energy CC lifters (named 822-16). I dont know why but this set of lifters behaved far worse. The noise was louder infact several were almost collapsed or with a big free play under the pressure of a finger.
I wonder if double valve springs ( 924-16 Comp Cams) are the problem or the high lift cam or geometry of valvetrain ( I have pushrod a bit shorter than they should be in order to get a centered line on valve stem)
Sorry I this post is long and boring, problem is where I live, nobody is a specialist ofthese engines and parts eat a lot of time-money.. Thanks anyway