Building a 56 Ford and looking at a Mark motor for it. It has 100K on it is that too many miles or are they good for another 100K? It came out of a clean car. I am new to the 4.6 motors. I want something that I can depend on when we go out of town to the rod runs that wont give me problems. So I need to know before I buy one what to look for or if there is anything that goes wrong with them? Thanks for any help!!!!!!!