I think the boost is fairly limited by the pulley ratios so there wont be much engine taxing. Moss claims a 50% torque increase. And its all over at 5700 rpm so it will live.
They use a HIF carb, which there again might be ok with low boost. Carburetors and boost are sometimes uncompatible at high boost pressures.
What would be nice would be a cam that would have more exhaust timing, some forged pistons and definitely some decent head studs and i would use a MLS head gasket also. maybe a larger crank pulley also??? 10K would cover a real nice dedicated lump with the blower....
plus your labor....of course!!.