I noticed that Summit lists the thier 440 cam will not fit a 1966/67 440. What was different in the 66/67 cam? I have a 440 built by someone else and the hydrolic lifter is compessed .150 inch off lobe (seems way too much). I'm used to chevys where we would expect about .030 inch colapse in the lifter. What would I do if a correction was needed to the push rod? Mike