Originally Posted by
Opossum
My engine currently uses a square bore carb. I'm thinking of I can find 2 or 4 good side draft propane carbs of the right size and design I could make a spacer/adapter to mount the propane carbs on the side of it with the original gas carb on top so I have the option to use either or both depending on how I set my linkages.
The simplest solution would be to use an Impco Model 300 mixer as it is designed for dual fuel use and adapters to mount on top of your carburetor are still available. As for how they work, there is good explanation in the beginning of the Impco product catalog.
The challenge with dual-fuel is optimizing timing for each fuel now that Dual Curve is out of business.The simplest solution would be to use a propane-specific advance curve if you're going to make it your main fuel. Fully programmable (like MegaJolt Lite) with 2 advance maps is another option.
Using bulk propane from home isn't really an option as you would need a propane dispenser to fill your truck. It's a much better idea to get a motor fuel account with a local propane supplier.
As for whether it's worth it, like jimandmandy suggests, it depends upon fuel prices and how much you drive.