Newly Built Ranger Death Rattle

[robert ray69]

Hello folks. This has got me stumped, and before I pull the motor, I`d like to get some opinions. Background, fully built 2004 4.0sohc Ranger, supersix heads/cams, pistons 10:1, polished and balance rotating assem, arp everything, Explorer Express SC kit 9-10# boost, ported/polished SC, water/meth injection, 50 shot of juice for the track. Just shy of 500hp to the wheels. When I rebuilt the motor all new timing chains, guides, tensioners, etc, Ford OEM new, went in. I have the rattle with less than 1500 miles on newly built motor. Been to the dyno for the tune and that's it. Weekend driver at best. Have not seen track yet due to rattle. I`m stumped. Of course I cannot pin point where its coming from. Quiet as a mouse on start up. Cold rattle between 2800-3000 sounds like hissing spark knock. When I push in the clutch to change gears, it changes the sound/tone of the rattle/hiss until clutch released then goes away and comes back when hitting 2500-3000 again. On freeway I can control the rattle by throttle right at 2900/3000, and it does not seem to go away. Rattles warm as well. Changed out hydraulic tensioners (easiest obviously) and it actually moved the rattle up the rpm range to where it is now. Brothers I`m stumped! Over 10k in a newly built race motor that sounds like a ticking time bomb. About to throw a torch at it. Could a brand new guide/cassette/tensioner fail or break already? Motor ran up to 6200 on dyno btw. What you guys think?

Oops. Believe I posted in wrong section. Mods could you please move for me. Thanks.