They are stock replacements for 4.6 2V engines. They do not require a gasket. Are they an upgrade? Some have had a problem with the seals blowing out of the stock plastic tensioner on the 3V, causing loss of chain tension. The solution to that problem is to install the 2V metal tensioner. Now. Some have had a problem with the metal tensioner ratchet mechanism causing excessive chain tension and breaking guides. I know guys running the 3V tensioners without issue, I know guys running the metal tensioner without issues. I think if you are going to eliminate VCT and plan on running a high volume oil pump or thicker oil you may be better off with the 2V tensioner.