THIS TUNNEL IS MADE TO FIT WITH OUR 35/36 CH/OLDS FLOORBOARD KIT (PT. #CVO270). THIS TUNNEL WILL REPLACE THE CENTER SECTION OF THE REAR FLOOR IF YOU NEED MORE ROOM FOR YOUR DRIVE SHAFT. 2" TALL; 6" WIDE; 36" LONG. INCLUDED WITH THE KIT IS AN END CAP THAT TIES THE TUNNEL TO THE FLOOR.