Around 2000 rpm upon acceleration it sounds like I have a boost leak coming from the back of the engine in the center of my dash. The head gasket isn't noticeably leaking anywhere and my coolant level is good. I replaced the intake horn gaskets, intake manifold gasket and put new intercooler boots on. I'm thinking the head is lifting, due in part because I swapped my HY35 for WH1C with an aftermarket wastegate set at 35 psi. And no gauges...yet...maybe it's just more air sound I don't know, wastegate?. Any thoughts? 

I doubt you are lifting the head. I ran my Banks system for about 8 years at 33 to 34 # of boost with no issues. I would go back a check and be sure you got all the boot clamps back on and tight. Double check your intake bolts for tightness and anything else on the intake system you messed with.

Exhaust leak somewhere?  I would check the manifold gaskets.

It sure sounds like you have a boost leak. Start the truck and open the hood. Grab the throttle and run the RPMs up. If you have a boost leak that you can hear going down the road then you will hear it with the RPMs up. IF you were lifting the head you would have anti-freeze problems and oil leaking all over from the compression blowing it out.

Do you have gauges? You are not going to lift the head at that boost. Our sled puller was hitting 48psi with no issues. Check all the injector line hold down bolts and intake plate bolts. When those leak, they sound just like what your explaining. Ask me how I know, lmao

Most likely an exhaust leak, check the clamp on the down pipe at the turbo and or look for soot around the exh manifold to head area or a cracked exh manifold.

^^^^ this 

open hood, pull on the accelerator cable ...... looks for soot comming out of the vband clamp

you'll need to reseat the turbo and clamp to get a flush fitting.......

 

Can also look for a missing bolt - usually in number #6

How big of a crack does it need to be to have such a problem? I've got a cracked exh. manifold...