Unisys12 pinned post is good info and advice. If your going to do it I'm sure he'd recomend replacing the valve-body with the Sonnax, they have come up with all the fixes and the ATX will last much much longer. It's done by my friends shop on ever CD4E. "unisys12" has done a major amount of home work.
If he does see your post send him a direct note (PM).
He's likes to help!
Paul
