cr of weisco pistons
I dont see where they would be for a 347 as the comp would be 6 or 7 to one
Also a 4.125" stroke with a 6.125" rod with .045" gaskets and the same 58cc heads makes a 9.5 to one 395 inch. Problem with that combo is the pistons rock hard on directional change and are also pulling out the bottom of the sleeves so they tend to use/burn oil in fairly short order. That is why most people stick to a four inch stroke or less and prefer to use a LS2 or 3 block which has slightly longer cylinder sleeves.
IIWY I'd build the 374 and either cam it small to maintain some cylinder pressure & possible spray every now and again or turbo it and keep the rpms under 6500.

