ONE thing To be sure to remember Is Not to over tighten them Bcause You can crack out the end and Hit WATER. This area at the end of them studs is NOt Very thick. Use some type of sealer On the Threads Just for safety.(if you happen to over tighten then it will keep you from haveing a water Leak) Also On some Heads The Front one Is Open to water right from the start. And the treads Must be sealed. Hope this helps.}[oooooo]