'Ran BITD Vegas to Reno with a friend in an MJ last month. We learned a LOT. Mainly, the "go fast" guys use an entirely different setup then the trail/4WD and rock guys.
If you read the rule books for the different classes, most of them have suspension travel limits. Example: BITD class 7100 10" max front suspension travel.
Also, most of the class rules require "stock style/type" suspensions or "stock parts: may be modified for strength. In other words: If it came from the factory with a 4-link, it runs with a 4-link.
The whole point of the long arm kit is to increase travel, usually because you're trying to crawl over a 3 foot tall rock. In desert racing, you drive around the tall rocks.(or drift around them, as the case may be)
Jeepspeed rules allow any suspension arms that are widely commercially available, keep the axle within about 1" of the stock location, and are "factory type" ie: 4-Link There are a couple long arm kits approved for use.
Our truck was a BITD Class 7100 entry: "Stock mini truck, modified" We were running against a butt load of Ford Rangers.
The front suspension setup was:
Roughly 3" lift, combination spring and spacer
33" tires on 15" wheels
Stock control arms
Stock track bar
Stock sway bar, connected
2.5" dia. remote res. shocks(14"travel)
Limit straps set at 10"
Rear was:
Spring under axle
Deaver springs
No sway bar
2.5" dia, 16" remote res. fox shocks
'Don't remember what the limit straps were set at.
http://durkadurka.net/photocart/index.php?do=photocart&viewImage=23427
Our top speed was over 70mph, and the suspension worked great. While he is making some changes to the truck, the only change to the front end is new bump stops(trying to figure out a cheap way to get hydro bump stops in there)