Well I got some time today to swap the power valve and enlarge the power valve restriction size. I changed the PVCR size from stock .060" to 2 numbered drill bits up to .067". I also changed the power valve from a 6.5 to 10.5 and now it runs FANTASTICALLY.

I used to have a large lean hump from anywhere between 10.5" and 6.5" of vacuum but now that is completely gone. It does however stutter if I stab the throttle fully but that seems more like a accelerator pump problem. If I do a normal controlled hard acceleration and roll into the throttle relatively quickly, it starts at low 13, jumps to low 15 and rolls back into a low 13 or high 12 as it gets into boost. I know it might need one more size up on the PVCR but I'm going to wait until I finish out the new fuel system and get it installed.

All in all... the 10.5 power valve and two size jump on the PVCR size did wonders. It runs great but I just can't stay in boost or it runs out of fuel in the carb.

69 Buick Special Deluxe. Intercooled Turbo Chevy 250 @ 15psi on a stock long block. It's kinda fast.