One thing I can say is the deuce will be under powered. I had the M109 box on the back of mine for about 3 weeks before I went back to a regular 12' bed. I hated driving it with the M109. 50 mph down hill with the wind behind you. I had mine turned up as high as you could go without meltdown. Last problem is the trans, pulling extra weight with a crew cab 6x6 I don't see it lasting that long.
I have a few questions so bare with me.
First, you mean it was under powered just having the 109 on the back right? Not that it was under powered with the 109 and pulling a load?
Second, with the CC set up with the 12' bed, how was her performance? Good acceleration with no load? With load?
Third, are you basing your results off the factory multi-fuel and 3053a?
Sorry for so many questions. But I'm putting together a 12v Cummins with a compound turbo setup to power this thing. Similar to HanksDeuce but I'm going to beef up the Cummins more than he did. He also used an Allison trans from a school bus that isnt rated for much torque. I want to keep the 3053a with a different housing to bolt to the Cummins. With that in mind, what kind of hp/Torque can the Spicer handle? And are there performance upgrades for it or will i be looking at a new trans soon?