72 Demon

We are planning on using the original filler neck also.what we did was cut out where the spare tire goes then put a piece of flat i think it was 16 guage sheet metal with a cutout for the cell,centered it up, welded in the sheetmetal then welded the bottom brackets for the cell to the sheetmetal , smoothed out the cut edges with a grinder, got a piece of vacuum hose split down the center, put it along the edges then droped the cell in, put seem sealer around the edge all the way around it then just put the top brackets on.If i get over there today i'll try to snap a few pics in the trunk and under it for ya.