According to the information I have, the final drive ratio on this vehicle was 4.3:1. That means, for every revolution made by the wheels, the driveshaft (which links the transmission to those wheels) has to turn 4.3 times.

IT'S A hard call. You'll be about $1500 out of pocket after you get the rebate, which means you need to add that to the price before you break even. When you do that, you're reducing your potential market of possible buyers. I think the Rodeo will appeal to a young tradie, and as such it may have more appeal as is with its lower selling price than it will if you fit it with LPG and increase the price. I would sell it as is and let the buyer decide to fit LPG.