The original question was: what is the difference between a 13 5/8 and 14" ladder?
The shorter ladder will pin the car on the RR. When you go into the corner, the car rolls to the right, the arc(length) of the ladder determines how quickly the center of gravity will move upwards. Think of it like this, the shorter the ladder, the more likely the car will bicycle on entry. If you get really good sidebite, use a 14" to slow down the raction time and make the car easier to drive. If you run a swaybar in the front, you probably need a shorter ladder. If you only run four bars, use a 14" ladder to keep the car planted. Jack and JJ used to "spike" the ladder when the track was really slick. Basically just putting a six inch strap in the top and readjusting the clevis. It REALLY makes the car get sidebite. Ladders at the track aren't marked, so you can't really tell who runs what. A slick way to tell is to look at the birdcage. Sometimes guys will machine off some of the birdcage to accomidate a larger ladder on a car that gets really good sidebite. But here's the problem; the younger drivers always want the car tighter, tighter, tighter. They would hate the longer ladder. They eventually learn that freeing the car up will make it easier to drive and a whole lot more predictable. Changiny the ladder is an easy way to "calm" the car down. Lots of info here but its no BS. Ladders aren't rocket science and they do matter, but I'm almost sure everyone could improve on something else before the ladder needs changing......