3.9 Liter V6 Swap

I Have a 92 DAkota with the MAgnum 3.9 with over 250K and the valve covers have never been off . The best I EVER got was 18 mpg in a high state of tune.

I have a 96 Dakota with a 3.9 and a o/d auto. I have gotten 22 on the highway more than once. tmm