the 4.2 doesn't have the Bottom End built heavy enough for heavy truck use.

On the 300 I6 take away the smog and put a better exhaust on it is good for 170-180hp. They were rated for 170 before 74' when the smog crap came around.

my dad has a 4.2 and it is a good engine for what he does. Mostly commuting and a little hauling. For me when i work on the farm in the fall for my buddy after school i need the torque of the 4.9 or a diesel to haul tobacco slabs on a g/n.

DT