AllmotorEH2

ok so here is my issue. a block i have has steal orings.... and is assembled and am not trying to deck it. My question is will i be ok with a oem head gasket or is it a must that i run a copper one. And if it is a must for the copper do i also have to have my head cut for the oring? i havnt dealt with many oringed motors and that is why i am turning to you guys. any help would be greatly appreciated thank you
Joel