LPG Gas Conversion

When I first got my old SIII someone many years ago had converted the engine to run on LPG. By the time I got it the tank had been taken out, the engine had been changed and the conversion was disconnected and in a sorry state. I removed all the pipework and equipment and binned the whole lot. I got the truck running on petrol and now I am thinking of doing the conversion again. Im a mechanic and think it would be easy enough to carry out. Problem is, where do you go to get all the kit and what all is needed. I have been told of a few bits and pieces that I need but dont know where to source them. Anyone done a conversion or know where to go to get the info for such a conversion........