Motor breaking up past 3000 rpms. Gurus I need your help!!!

[Miguel]

My motor seems to be breaking up past 3000 rpms in neutral and running, by breaking up I mean rpms are going down between 50-200 rpms. It doesen't backfire but makes like a slight air puffing noise through the exhaust when rpms pass 3000. Checked fuel pressure at 7 psi gradually goes up to 12 at full boost from a procharger making 7.5 psi. Checked timing and when I lowered it to 7 degrees it made white smoke come from tail pipes and still broke up in same rpm range, going to 20 degrees initial stopped the smoke but same reaction. Temperature is at 150, oil pressure is 42, volts 14, boost at 1000 rpm idle is 2 psi. Filled the tank with gas and carb cleaner, no difference, Spark plugs look tan color and everything looks good. I have a new 393 with a intercooled procharger, Dean Nickerson 750 cfm holley carb, Boost referenced fuel pressure regulator, 130 gph mallory electric fuel pump, 1/2 fuel lines, 4" Open exhaust, full MSD ignition distributor,coil,6AL and a bunch of other mods. What could it be, because I'm stumped? Any help will be greatly appreciated. Thanks.