It doesn't even have to have an off road drive train. Mix in a 4L80 and diffs tough enough to handle the tq and be prepared to be disappointed numbers wise.

You need to upgrade the whole top end (including heads) to take advantage of the extra cubes. Ported 317's or 243's at a minimum. LS3's or aftermarket castings even better.

 

Dru is selling a ported TBSS intake on HoustonPerformanceTrucks for 350!
That's a pretty good deal.