Horsepower

If you work in a junk yard why not look for a 5.9? You will get more power easier than with the 5.2.

If you go with a 5.2 at least rebuild the engine with some high compression pistons from the likes of Keith Black or Speed Pro and have the engine block decked to get the pistons to zero deck. All the magnums have roller cams so take advantage of that and get one of the new Comp roller cams. NOTE: if you go beyond .525" lift the guides on the heads will need to be cut down for clearance.