from my studies....

the kits consist of: a 4 or 5lb reduced stiker spring,(lighter springs needs an ultra light weight striker because of light primers hitting) reduced power firing pin safety spring, high polished ffiring pin safety, an extra powered trigger spring, a polished 3.5lb connector and some way to prevent over travel. Delux high dollar kits include a new trigger/bar set up.
On mine, I polish the crap out of everything and install factory 3.5 connectors and use "Super Lube" synthetic grease. This works for me.