I think what your looking for are these, but first don't know the seller, this for your information only;
http://cgi.ebay.com/ebaymotors/ws/eBayIS...TRK%3AMEWA%3AIT I've seen these referred to as propane pistons. The buyer does give some spec.s and an Ertel part number
Larry
68 C20 327 daily driver
63 C20 292 Camper truck
65 C10 ? Custom Cab AC,PB,PS,$flasher - Project
