273 2bbl turn into Commando or is 318 better?

What would be needed to upgrade a 2bbl version to Commando spec's? About the same thing as would be needed to make the 318 interesting, cam, intake, and carb. Both the Commando and the 2-bbl are solid lifter motors. No one is making the cam and single plane intake, so you're left with the inconsistency of the salvage market.

Would that be a worth while option or do you think a 318 would be better or just more cost efficant? As a driver, I think, the 318 would be a better choice. The power is more abundant lower on the rpm band, and unless you really get aggressive with compression, it will run on regular gas. The 318 is also uses hydraulic lifters which means an easier build and less maintenance down the road.

The Commando ran a 10.5:1 compression ratio and used a domed piston. If you're looking to create an authentic Commando where none were delivered, your parts are coming from here. The pistons are available in reproduction ($$$s)

You'll have the advantage of a wider choice of components for the 318. You may find a local stocking outlet for the carb. Since Mopar doesn't seem to have a big presence in Australia, like Holden and Ford, you'll probably have to come to the US for the intake and cam. All the US retailers want is your money and a satisfied customer.

Very intersting ute. Good luck & G'day mate.