You are correct, I have a magnum bolt pattern intake. No, I haven't drilled any magnum heads to accept the LA intake. All my builds have always been LA motors. The 318 mag I have on the engine stand has been there at least 4 years. I've owned several magnums in their factory vehicles, but I have yet to do the magnum swap. It will happen though, someday, ...... maybe... LOL. I have the roller cams with fuel pump snout, I have the intake, I have the 360 oil pans and pick ups, but just haven't got around to it.