well i found a car the other day good shape what i am looking for. 94 grand am GT good shape 96k on it. but when i popped the hood i noticed the Quad 4 engine in there which i know has a reputation for blowing head gaskets. which is what will happen when you try to make a high output 4 cylinder engine with some [non-permissible content removed] mechanics behind it. my question is if i get the head gaskets replaced will they last for very long or what would be the cost of finding a 4 cylinder twin cam or a DOHC and putting that in.