I agree with Tommy...all engine mounts from old to modern use three points of attachment to allow for engine/frame twist. The old truck had two mounts on the bellhousing and one at the front, new setups use two on the engine and one at the rear of the transmission. If you plan on keeping the original bellhousing with it's two side mounts and then add the engine side mounts you'll have 4-points of attachment which will resist twisting until something finally tears apart. So, unless you're swapping to a modern transmission you should drill and stay with the front mount.
Mike B
