What fuel will you be using? E85 or pump gas?
Typical 408 stroker kits have a hi comp ratio for boost. W/M injection will help with this issue.
A custom piston for the 408 with a huge -40cc dish would be needed to drop the CR .
I run a 387ci 360 with a 3.79 stroke K1 crank. 2.1 rod journals , .927 pin, K1 6.125 rods. An off the shelf -30cc Diamond 2618 Forged piston from a 383 stroker chevy with slightly modified valve pockets, only $8 extra charge. 2618 alloy is great for handling boost.
I'd recommend using full Grove main bearings to provide full time oiling to the rid bearings. I'd also recommend ARP head studs and a serious head gasket. I use SCE copper head gaskets , my heads are O-Ringed and have a receiver groove cut in the deck of the block. That will hold any cylinder pressures.