Sounds as if a deal is going sour fast,first you need to see if its a 4 mill,before you buy a head.You have to have the head cut for it if you use a stock one or buy a noss or coolhead with cut domes for a 4 mill and at what compression you want to run will determine the cc domes you need,also need to know what the rod length is on the 4 mill 110 or 115.Check it now while its down and may save you alot of headache later..JB