Even witn an angle drill, I could not position the drill to get to one of the holes in lower center of the engine mount. I bolted a 2x4 to the engine mount using the inaccessible hole and then drilled the other three holes through the 2x4 using the engine mount as a drill guide. I then bolted the 2x4 to the firewall with the three holes that were already drilled and used the 2x4 as a drill guide for the final hole.