Hello! Great site. Been lurking around for a while. Lots of good information here. I've been a Ford man every since I could drive. From Falcons, Fairlanes, Torinos and Galaxies. This is my first truck, if you don't count the Ecnoline 200. I have a 1975 F350 Ranger. It's also the newest Ford I've owned. I really like it. It's currently set up to run on propane. It seems to run well, but I'm having trouble passing smog. It seems there are a couple of components missing. The smog guy wouldn't pass me on the visual so he sent me to a referee. The ref. said I need a vaccum reservoir and a vaccum amplifier. The amplifier is supposed to hook up to the carb venturi vaccum. But information I have found says that these LPG carbs/throttle bodys don't have venturis. The guy I bought if from doesn't know either. He said it passed smog before. In Ca. you can access the C.A.R.B. web page and get lots of information on how to pass smog. There is also a page that has your vehicle history for smog. Just enter your vin number and it comes up. I did mine and sure enough, it passed the last three times. Very usefull before you buy that used truck. However there is very little information on propane conversions. So I'm stumped. I guess I'll have to find a machanic that knows about these systems. Has anybody out there running propane run into this sort of thing? Thanks for your help. And again, great site.