The hump pretty much centers itself on the tunnel. Lay it in place and trace the outline w/a magic marker. Trace another line approx. 1.5" inward from the original outline and cut away. Do not cut thru the structural support. It's a big hole but you need clearance for the 1-2, 3-4 shift rods as they are above the structural support and skewed towards the left. The rev. rod goes underneath the support. Mount the b/h, trans, shifter w/handle and lay the boot over the handle then on the hump. Mark your final location. The left rear of the hump DOES NOT seal properly to the floor as you can see in the pic so you need to patch it. I installed a repop'd hump. Weld every 2-3" in place and apply seam sealer on the top and bottom.