Hey bud, did you end up moving the axle forward a bit on this truck? As the axle is moved forward the front height does change a little unless you shim the front of the axle to account for the spring bend.
Another alternative would be aftermarket shocks. My dump truck had almost no rear suspension travel with the stock set up and a empty box. After installing shocks with adjustable spring tension the truck rides much better. They would work great on the front of your truck and the fact you can't really see the front shocks unless your looking from underneath won't take away from the scale look and fix your front bumper problem.
http://www.ebay.ca/itm/ALLOY-FRONT-S...p2056016.l4276
Mario