If you really want to go Cummins you could swap one in where that IDI is. It can be done economically, if and only if you can find a fairly complete Cummins truck to strip for parts. If you want that power you need a Cummins, cause I doubt very much that an lightly turbocharged IDI will ever keep pace with a lightly modified 12V Cummins. The potential biggest headache would be mating your transmission to the Cummins, but there are definitely ways around it, you could use the Dodge transmission which is not too bad of an idea if its a manual or if you have a ZF5 there is supposedly an adapter to make it fit the Cummins, not real cheap but Advance Adpaters is said to make them. Not sure if an adapter exists for the E4OD but then again they have enough trouble handling a stock N/A IDI(mostly computer and electrical but still...) My vote would be for a Cummins swap or just drop a turbo on yours if you can live with the slightly lower power level. The truck will respnd very well to turbocharging with that low of mileage I doubt reliability would be affected at all as long as you watch your gauges. I like the non wastegated kits like the hyperma because you only make a lot of boost when you need it, dragging around town its very little and thus doesn't stress the motor until you come to a hill say or need to pass the slow guy, then you have boost. You also clean up the smoke emissions quite a bit while gaining power...how many things can you say that about??? Hypermax is top notch, consider going through forum member "Huff" if you buy Hypermax, he'll definitely treat you right.