Anyone running Propane, or thinking about it?

I used to work with a guy who had converted his chevy truck 350 to it. He had a big ol' tank in the bed a little bigger than your average diamond plate tool box. He said it definitley had less power but he could live with it. He pulled the dipstick out & showed me what looked like fresh clean oil on it but claimed it had nearly 50,000 miles on it & all he would do is add some as needed. Because it burns so much cleaner than gasoline it doesn't have the deposits that ordinary fuels leave behind. It was interesting, but he also had a gas station that sold propane so he wasn't paying retail prices for it either.

I suggested filling it with acetylene & going racing with it! He declined. I wonder why?..