You need to know where you are with all measurements, before you decide what to do.
Go to my tutorial, and you can then come up with your plan of action. If you dont like the clay usage, you can use small aluminum foil balls positioned in place with grease, as some others suggest. I like clay.
http://www.flatheadv8.org/clayhead.htm
Find out where the problems are and then we can recommend a solution