the engine converson in 1988 cost $6000.00[engine included]then in 98 did the us gear vender over-under aux trans and change rear gears to 3;50's..i'm thinking i was into that about $2000.00;;;i'm thinking it can be cheaper now..with the dodge trucks having cummins in them a person can go to junk yard and pick up the engine from a wreaked dodge truck..also most all dodge trucks with the cummins has the 3;50 rear gears.look for the older ones because they don't have the computter control fuel systems.then buy the us gear vender aux trans..they are still on the market;;i heard the new news are quicker and easy on drive trains.mine is one of there first ones so when going up or down on shifts it crunks hard...sometimes i can catch everything just right[rpm]and it doesn't do it harderly.