mracura

i have 8 extra ls pistons and rods and a set of b16a rods with ls pistons on them. i possibly have 2 bad pistons in my motor right now, i just took the head off today so i dont know yet. but what should i do if i build it back using some stock parts would it be better to try to lower my compression or raise it? i'm trying to do it right so if u guys that know how to can help me i appreciate it. also what are some ways i can up my fuel? thanks.