Nick here's my take, and Pat correct me if I'm wrong, I've been away from drag racing for 18 years.
Anyhow, what we want to do in any form of racing, is to maximize the weight transferred to the driven wheels. In conventional drag racing (2WD), at launch we want transfer as much weight as possible to the rear driven wheels, only allowing enough weight remaining on the steer tires to maintain control, thus, we want to minimize rebound dampening.
In 4x4 drag racing, since the front axle is also driven, and very heavily loaded statically, we want to MINIMIZE weight transfer to the rear axle. In this case we want a front shock to have heavy rebound dampening. This is a little tricky because one size can't fit all, dampening will be somewhat of a function of weight and horsepower (or torque). Too stiff, and it will act like a solid link, raise up, jerk the tires, and bounce the front end. Too light , and we will hit the rebound limit (or other suspension travel limit), meaning damaged shocks, bouncy front end, etc.
Ideally the front shock should be just free enough to not "solid link" the front end. Something valved about like the Bilstein be5-6243-h5 might be interesting to try (4000/1000 @ .52 valving).
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