I wouldnt stack em but i understand u want to keep your gauges on the banks, i would turn the banks all the way down though and just use the gauges for the smarty. The best stack for the smarty is a ts mp8 for a pressure box. if your going to though just unplug the 6 gun from the obd II then download the smarty then plug the banks back in. I didnt have gauges for a while when i first got my smarty and ts mp8 so i just left my edge module in there (which plugs into the obd II also) and just used the gauges on the edge but turned the edge off. Kind of the same situation.