Calculating home made truck engine generation by BUTANE power for BELIZE.

TOYOTA TRUCK ENGINES AS ELECTRIC GENERATOR USING BUTANE

I´m wonder how the cost of butane gas to run a pickup truck engine would be if converted to running an electrical generator? In Belize we have many converted pickup trucks, using BUTANE for their fuel. They keep a 100 gallon tank in the back pan of the pickup, connected to the engine. There are a number of individuals around the country in Belize, that will convert a gasoline truck engine to using cheaper butane. Many go this route.
I presume they must be saving significant amount of money, to go to the bother?

What struck me today, was the idea of using a pickup truck engine, connected to a generator. Not sure how you would do that with a gear box involved, but certainly it is possible. THE QUESTION ARISES, WOULD THIS WORK FINANCIALLY AND COME OUT A LOT CHEAPER THAN USING A DIESEL RUN GENERATOR? OR FOR INSTANCE, TRYING TO BOIL WATER, TO MAKE STEAM TO RUN A STEAM ENGINE CONNECTED GENERATOR.
You could probably buy a 1000 gallon tanker load of BUTANE from Guatemala and run such a gasoline engine generator. The thing is, the question, WOULD IT PAY A PROFIT? If you sold the electricity to the NATIONAL GRID? How you would do the pricing on the fuel bill, plus outgoing electricity costs, as a study is presently beyond me. Anybody got any details would appreciate it?

The 4 cylinder Toyota gasoline pickup, produces 106 hp at 79 kw at 5200 rpm.
The Toyota Tacoma pickup engine produces 142 hp 140 kw thereabouts.
The 2012 model engine for the TACOMA pickup, is rated at 159 hp.