First off, how long has this truck been sitting? Did you allow it to warm up completely before you decided to check the plugs? Was the oily plug loose? Maybe seepage down the threads.  Try a new set of plugs to get a more accurate idea what is going on, warm the engine up before you put them in. Consider an engine that sits for an extended period can develop many problems, like sticky rings.  If the carb dried out so many things can be going wrong there, carbon buildup is one. I'm not too versed in propane, I do understand there is a dropoff in power. If you are planning on just running propane you could increase your compression ratio, look into the octane equivalent of propane to gasoline to get an idea where you can go with that. Where are you located?

I'm in Northern California, Sacramento area. With all the options I think I've got it narrowed down to what I'm gonna do.

To answer your question no. I wasn't able to get the engine warmed up as I wasn't able to keep it running long enough to get it warmed up. The engine had been sitting for well over a year since it was ran last. The guy I bought it from was having a ton of trouble getting it Smogged so. Tuning, Carb issues and plus the fact that it has been sitting for a long time, I'm sure have several things working against it.

I spoke to the gentleman at Engnbldr.com this morning and explained what I was trying to do. Man what a nice guy, he must have spent over 45 minutes on the phone with me explaining my options and his opinions.
I have tendency to want to get everything done right now. And because of that I usually rush things and regret it. I don't want to spend a bunch of time and money on this engine deal but I think in this case I don't want to rush and cut any corners. I'm convinced now that a 20r/22r combo engine would be the way to go. I'm going to build/rebuild an engine from the ground up. So I know what I've got and and I know what I'm working with. Even though it may take some time to gather all the parts and pieces ($$$$) I think this is the best route to go.....  I mean yeah I could probably get by with the 20r.. but I don't want to be kicking myself in the future thinking "I wish I woulda" been there done that several times... I just wanna do it right the first time and be done with it. So this'll be my first step. I guess I better start a build thread on this puppy!

I appreciate your time and input!