#1 At What horsepower level would you need a sway bar in the rear with a 4 link car?
#2 Does it matter if the sway bar is in front of or behind the rear end housing?
#3 Does it have more effect if it is in front where the bars are atached or in the rear where the shock attaches?
#4 Do you install any preload or is that a car by car set up?

#1 doesnt really matter what ET you are running a "anti roll bar" if set up correctly will help any car.

#2 no it can go in front or behind. Its only meant to keep the rear end s square in the chassis.

#3 no shouldnt make any difference but I always attach them to the housing.

#4 In a 4 link setup I NEVER try to preload the anti roll bar. I set the preload with the 4 link then after that is set I zero preload the anti roll.

Good info
Thanks