Actually, a lot of people use only 4 valves, but they usually use sway bars too to keep from leaning. But, you are right; individual valves for each front side are definitely better and will eliminate the roll. You don't necessarily need individual rears, but that's your choice.
Lean is definitely an issue with a 2-way setup... This guy had resorted to elevator weights under his running board on the p***enger side just so it would sit level That only worked of course until a p***enger got in. He's definitely a believer in a 4-way system now!
The Jalopy Journal
