There's a company that is creating a tag along single axle for semi-trucks that seems to have components that we would need to do this. It's designed to move an 80,000 pound semi-truck 250 miles. Target price in volume is $50,000.00...
Here's a YouTube video on it:
https://www.youtube.com/watch?v=XSB3WaeolcU
And the company that is going to make it.
https://drivetandem.com/
If you yank the engine/transmission/cooling system and the fuel tank I would think that you have enough installation volume to add this.