Ticking/knocking noise at high rpms under load

Well i had this noise for a while now on 04 ISX 475/1850 with 13 speed. If i floor it pass 1400 rpms and make 20psi+ boost it will start ticking/knockin than it will kinda quiet down pass 1700. If i go down hill and let it roll by it self pass 1400 it wont make that noise. Only when i apply trottle 20psi or more. Inframe was done at 1.370.000. Didnt replaced cams or any of rockers since mechanic told me they were good. Head was replaced together with air compressor. I didnt have this problem before overhaul. I had some gaskets start leaking on front cover so same mechanic install new gaskets and i bought two idler gears with bushing. We also replaced 3 front jake brake rocker assemblies since they were moving at idle. He also inspected cams and said they were still good. At the end he adjusted top end. Engine didnt make this ticking noise for like a day than comes back
I cant make tick at idle since turbo wont spool up pass 5-10 psi when i rev it and i had limiter at 1500 at ilde. Btw limiter in low range is 2000 and 1800 in hi range

 

I didnt know ISX have lifters. I know i have overhead cams with rockers on top of them

 

I hope not its not cam. What socket do i need for the crankshaft

I bought this truck with 570k and since than i have runing same rpms every day, 1450 at cruise 65mph. Maybe it have some kinda pattern and int ballanced after that. I know it sound stupid. But what it gets me is why is doing it under mid or hi boost under throttle but not if i going down hill by it self without using throttle. No noise even at 1700. Just under the boost 20psi+ and 1500rms+

 

Im listening right now. I have cold temp fuel knock at cruise becauze its 28f, boost at about 7psi, i can hear that fuel knock from under the dashboard which is from the head. Soon as i hit hill boost goes up, fuel knock goes away and than i start hearing this knock. I have driver side window open a few inches and to me sound like its coming from the left side. Air compressor maybe ? Its happening meybe like 3 times per seconds which comes to 180 rpm ? Whats spinning that slow at that speed ?

 

Yeah it gets louder 1500rmps+ under the boost. But why only under the pressure. Maybe turbo pushing air into air compressor and making air compressor piston go crazy. Maybe its impossible. Im gonna try disconnect air compressor inlet and pljg intake hole where air compressor gets air and try it out

 

This thing is crazy. If i hammered in lets say 13th ger from 1200rmps and go pass 1500 noise is gonna be quiet at 1500. But if let of accelelator pedal and hit it again its gonna be noisy.
Look like wont make loud nise when getting up to speed, just hammering from steady high rpms