What motor is in the machine to start with? Then does the motor operate with an ecm? Coil packs? If it's old school points and condenser. It's probable to convert. I'd start there. Any electronics that fires the ignition side along with fuel most likely not doable. If not it would take some measurements of intake components and if water ports are available. Needed for the vaporizer. Impco technologies can match up anything to fit your needs. They sell kits for this purpose. Measure for airhorn, throttle cable position, horsepower needed. That would tell you size of mixer. Ca55, ca50, etc. needed fuel for power. Intake opening, stud center to center. Updraft. Down draft ! What is on for a carb now. Sits on top of intake? Then downdraft. It's a real basic system. Room for a tank holder etc. fittings are basic if you know pipe thread and gas thread. Gas thread is different and brass only. 12 volt solenoid for shut off of LP. Hope this helps.

It is medium price, if you are experienced.first you should be certified
For LP ,second you need an LP kit and knowledge of L P and lastly if you are not familiar with LP/ gas conversion you really should get a qualified tech experienced in
Conversion to do it. So to summarize it can be expensive if unqualified and also dangerous
I have done dozens over the years and am licensed through state of Texas for repair/ installation you need to check state regulations
On installation requirements and licensing