I'm running 5012s front and rear. The fronts are like Marv’s (Steve has a write up on this site too). Most add a cross member and angle the shocks in to the center at the top. But this dramatically reduces the shocks ability to control sway in the rear. Not only is the rate reduced, but where they come together works like a hinge letting the body roll (to some extent) without the shocks getting involved (over simplified, but you should get the point). Also, any time you mount the shocks at an angle, especially when they are tilted in line with the axle movement, you effectively lengthen the shock’s travel. The rears on mine are different than most others I've seen. They are angled forward along the frame. This angle reduces the rate, and effectively lengthens the shock quite a bit, but it still provides more control than tipped to the center.
