whats up guys, ok i bought the car from a friend pulled spark plug and we had oil in 3 cyclinders pulled pistons out and two pistons were broke they are jdm civic type r .25 oversized. i was wondering if i can use stock ls head gasket or do i have to run a cometic one with 0.40mls due to piston valve contact si head btw the pistons are on ls rods and will compression be to high to run on 93 gas the car is tuned with neptune and timing is advance so if i were to change pistons to itr lets say car would run shitty correct? thanks in advance

si head mild port and polished
type r cams
type r valve springs
type r headers
ls bottom end pct oversized pistons
arp rod and head bolts
tuned with neptune