Totally different animal. I'll give you a couple pointers. I wish you much luck and all, but don't hold your breath for passing if you've never welded stainless before. Since you mentioned GMAW welding, for conversation sake, I'm assuming you're welding plate vs. pipe. #1. Make your joint fit-up as precise as possible. V-groove joints will close up 100 times more with stainless vs. carbon. #2. Hitting on fit-up again. You can not get away with ANY discrepancies in your prep. Things that can be done all day long with mild steel will not work with stainless. #3. Tack the heck out of it. Stainless absorbs and holds heat more than carbon. Each tack should be a minimum of 1" long. In addition, double the amount of tacks compared to mild steel. #4. Inter pass temperature is critical. Unlike carbon, you can quench stainless between passes. Hydrogen precipitation is not an issue as long as your voltage and feed speed is within the realm of reason. #5. I'm not sure what exact process of wire feed you plan on using, nor the wire type. At any rate, whether Short-Arc with solid core or Modified with metal-core, your travel speed needs to be; at minimum, 50% faster than what you are used to running Mig or Mag on mild steel. #6. Try and wait at least five minutes between passes.