Hey Mule 1951, I am going to order the 292 with the LPG pistons this week from Hiperformer, also known as S&S up in Spokane Washington with a 7/70 warranty. It brings the compression from 8.0-1 to 9.0 to 1 for better fuel economy and power. As far as I know of there is no difference other than the pistons on them. We ran a small fleet of rigs that were totally stock engines and were converted from gasoline to propane without touching the engine at all. They ran good but really needed the higher compression pistons to make them run even better and more efficiently. We lost about 1 mpg or so with propane. I had to fill my truck everyday when I got back for the next days run. The other thing that I am having done is balancing which with the 292 is a very good idea being its not a high revving engine but a torque motor. Keeps them together a long time. I am staying with the stock cam. Also they are going to do some porting and polishing which will allow more air and fuel in without going to larger valves or a bigger cam. I will also run headers into one 3" exhaust that I already have by Magnaflow. Quiet yet flows so very well. Lump porting may be an option later. Probably going to two single barrel carbs as I can hook up the two cables easier than a 4 bbl being I have a 700R4 trans and 4X4. You would probably like this set up very well. This is what I've decided to do without getting radical. It will run smooth. have plenty of power and get decent mileage. I hope this helps you out.
