I assume when you say "slide" you're talking round-slide. I was told flat-slides stick under boost if not properly modified. CV carbs are supposedly good for boost because they are already well sealed. Since the CV requires proper vacuum to work the carb is sealed, and all you need to do is tap into the bowl vent and the CV vent with a boost-referenced line. It sounded pretty simple, and there is a CV carb for sportsters that is about the right size for this.

Boost is not likely to see anything past 6 on this motor, for many reasons (cooling, timing, breaking primary chains, etc). I'll need a FP no matter which route I go. I was told the carb on the Rayjay setup can suck the bowls dry under boost, so you need a FP for volume, not pressure. For a blow-through I'll need pressure and volume. The regulator is, I assume, manifold referenced? Even if I limit the boost to 4psi, with 5psi at the carb. The 1psi difference may not be enough under boost to get enough fuel in, and if the bowls run dry the engine leans out and holes a piston.

The life-expectancy of the turbo in a "draw-through" setup is debatable. I've asked some of the guys on the dragbike forum and they all seem to believe 10-15k miles is not unreasonable to expect from it, assuming it is properly oiled and the air is clean, etc. Still worth considering, because it requires less clutter and difficulty. I'm looking into having my ATP exhaust manifold reproduced by a local header-builder. That way I would have one to cut up for a blow-through setup and I can keep the kit intact.