dang i sure missed my que on that one! Yes i have a 5.9 in my truck with 1600's (avitar pic). I think there is plenty of power to go around with the fuel plate slid. I need to do something with the turbo (hint hint). I run the stock tranny for now. I have a 600 lb class 18 speed overdrive but might opt for a 6 speed OD allison. My motor is realy a medium truck motor NOT a dodge motor. The dodge motors are differnt than than others. Every one says they are the same but they are not. Well, let me rephrase that "the same but differnt". All the dodge parts are of lesser quality (how many miles will a dodge truck last?How bout a medium duty pete?) Some blocks are a "c" grade in a dodge, same with the pistons. The part numbers are all listed for "A" "B""C" parts. marine beeing all "A" This theory applies to most parts. The medium duty motors are just plain easier to swap because they are all set up for "truck market" parts rather than "automotive". It is all changeable but with a dodge you KNOW your not going to get an aircompressor or the right bell and flywheel.
I highly recomend the swap. The B is 10x the motor as the multi fuel. Makes more HP AND more TQ with less cubes and a much better power to weight ration. I added hydro P.S. and LOST 140 lbs on my front axle. My motor came to me at 190 hp and 450 lb down around 1400 peak TQ. that was a little short to run 65 all over with, so i slid the fuel plate and pinched off the waste gate. BAM 38 lbs of boost and black smoke. Now we run 60 all over, just gota watch pyro and for overrunning the turbo.
The "c" series would be better like he said (8.1) Its more like a heavy duty motor with wet sleeves. I, however, couldnt get one with eveything for the 2K i paid for the cummins and chassis. My next idea here is that a B will put out 300 hp and 650 lbs fairly easy. Its cheaper than a "c" with that power. OK so it wont last as long, motor homes run lots of miles at 300 hp.
Now, i think, just a thought here, that that kind of power in low range will break stuff just fine with my tires (probably yours too).
My next point goes somthing like this. The truck was desingned for 50 mph! Have you ever gone 70 in one of these? I HAVE! the rear suspension shifts side to side (where the springs go in the axle) and evey time it does its a lane change. freaked the heck outa me and the copilot. Now if you run 55 or so its not near as bad, just a mild pull side to side thats hardly noticable. Im building air ride with panhard bars to solve this however.
For the price i think the B is the best bang for the buck. The 3208 is also a good one. Probably cheaper but HEAVY very heavy compared the the cummins. I had a 250 hp 3208 layin around when i did the cummins sawp but i figured in the long run the cummins would probably be better and have enough power to snap axles. Plus the front axle gets a little heavy for off road flotation.