High boost

[Yauchout]

I have a CM2350 factory 550/1850 demandated by a respected member of this form. My boost levels are higher than usual showing 40 PSI on the factory boost gauge on a hard climb 1600 RPM full throttle. I've done an injector leaked down test injector performance test installed a new IMAP sensor no engine codes truck passes both the leak down and performance test. Is there a test I can or should perform on the VGT to eliminate it as a problem should I hook up an aftermarket boost gauge to make sure it's just not a bad factory gauge. I'm not sure where to go from here