The main reason that SUV's and Truck's get a forward rake is due to hauling a load, that way the truck sits level after it's loaded down. Now not sure if that was the intent of the rake with the VX but it's possible. The only possible reason for having more forward rake be a good thing would be the driveshaft angle but in all honesty the tailshaft of the transmission sit more level with the output of the rear diff is what you want. Here's a picture for ya:
http://www.carcraft.com/howto/91758/photo_08.html
Having the rake would tilt the tailshaft toward the sky more so. I don't think you'd hurt anything by raising the front of your truck Rick