Funny you should mention that... when I first installed the factory turbo setup, I somehow got hold of the wrong seal (which was for a Holley 4-barrel carburetor to air cleaner, not the IDI intake-snail). Once I discovered and fixed that, boost went up at least a couple psi even with the old worn-out turbo
That was a big leak and it wasn't really detectable either!
I was going to check that this evening, but I couldn't separate the snail from the compressor outlet with the turbo bolted in place... best I could do was to remove the bolt, use a feeler gauge to make sure the seal was seated all the way around, and retighten.
The fitting that supplies pressure to the wastegate is loose in its threads, and the metal tube is also loose despite the nut being tightened. The packing gland probably needs replaced too.
Also I wanted to fix one stripped bolt on the airbox that's been bugging me for years - but the hole remaining (once the damaged insert was removed) was too big for a 1/4-20 Helicoil. I ended up putting in a 5/16-18, screwing in part of a 5/16 low-grade bolt, then carefully drilling and tapping it for 1/4"! I would have rather used something like aluminum or brass rod, and a lathe to center-drill... neither of which I had