I would guess a 14 or 16 cm exhaust housing maybe injectors. If it has the Banks intercooler that is a good piece and well worth hanging on to. But for the most part there are much better deals out there than the Banks stuff for the Cummins. Especially the first gens.
I would be very careful with the propane on the Cummins as well. Really not much benefit gained that could be gained by doing free mods. Full fuel screw adjustment and a timing bump with a set of PODs injectors and a fuel pin grind or set for max fuel and you can pretty much gain 125hp or so. Timing bump and propane is a definate no-no. Headgasket will say bye bye.
Good luck if ya get it. I hope you have as good a luck and as much fun with it as I've had with mine.