stock 346 with 243 head's and piston ?'s
 

i have a 346 stock long block and im looking in to dome pistons i do not want to change stock head gasket or mill the heads what would be a good +cc to be around 10.9.1 no higher then 11.1? i can add what else i have after i get a response if needed

Why on earth do you want dome pistons, but you dont want to change head gasket size??????

ive talk to gm about lowering the head gasket size and they say its a bunch of bs

plus more torq and hp

im never going to use any forced induction

Unlike SBC, LS owners seldom use domed pistons unless in racing situations. If you want to increase compression, thinner gaskets .040 and light mill. 61>62cc will give you 11:1 on stock gaskets.