I drilled the 6 holes for the engine mount. The top 2 holes lined up perfectly with the prepunched holes in the stainless steel firewall. Once I was able to hang the mount from those 2 holes I marked the lower 4 holes, then took the mount off the firewall to drill small pilot holes. The small holes were opened up with a unibit, then final drilled with the mount in place with a 3/8" bit. The 2 middle lower mounting holes will need a couple of washers to shim them to the firewall. The mounts in the middle for some reason are not in the same plane as the outer 4 mounts.