04 Hemi, If you expect to do a smarty stack I would suggest you get a fuel only box. the reasons for that are: Edge controls timing and so does the smarty, The smarty does a better job in that timing control, If you stack edge and smarty you will not be able to get all of the benefits out of the smarty, (you can only run the even number or fuel only programs), It can really mess your engine up if you run edge and smarty with timing enabled, ( and it can be tough to not turn the smarty all the way up to 9). The latest release of the smarty software allows you to select your injector pulse width, (yes you can do that on VP44 trucks), and also select your timing or just run a preset program. Now, lots of guys stack edge and smarty and like it, but they are not getting the full potential out of their smartys. If you do go the fuel only route, look into a TST, Van Aken, or Blue Chip. Blue Chip being top of the line for our trucks, but they are are expensive. If money is a big concern, I'd suggest finding a used TST power max 1 on ebay. Then spend 50 bucks to buy the remote for it and you can access all 9 power levels. All TST power max boxes are the same in programming, meaning all 9 power levels are already on the boxes you just need the remote to access them. I am in no way an expert in this field but I have been working on, building my own, and helping build other high performance CTD's for the better part of 5 years now. Also, this can't be stressed enough, the first thing that needs to be done to these trucks if you plan to go the performance route is lose the stock lift pump and replace it with a frame mounted aftermarket system. Also install at a minimum a fuel pressure gauge and egt gauge.