I have a 67 w a 351w. I am wondering if I can use 69 w or c upper motor mounts with my 67 frame mounts. The object is to lower the engine. Now I have the earlier 289/302 mounts and want more hood clearance. It looks like it lowers the engine .75 to 1 inch. Are the frame mounts spaced the same? This would be a simple, inexpensive mod. Mustangs Unlimited calls it a low motor mount.