you guys know that the intake in a multi fuel is surrounded by coolant right? so even if you put a inter cooler on it IT WONT DO A THING!
this has been talked about many many times. If the air temp coming out of the "inter cooler" is less then the coolant temp the intake will warm it up.. if it is more in temp the intake will cool it off.
sorry but there is not enough surface area in the intake for a significant effect compared to an intercooler. There are many many vehicles with coolant running through the intake and even without that most until recently used aluminum or pot metal castings that conduct the engine heat better than coolant.
the question of effectiveness really will come down to the nature of the multi-fuel diesel engine. The cooler charge effects gassers a lot differently than diesels, I'm mostly curious if the multi fuel can handle a significant power increase without snapping a rod.
asside form the search for more power, it "might" allow for more air flow and lower EGT for a cleaner burn. Don't think I personally would try for a bunch more power without some internal upgrades first.