In '71 after I got home from the Army, we stuffed a 440 Mag into my '64 Belvedere that had the old poly head 318. I can't remember exactly what we did for mounts though......With 2.73 rear screws she would get waaaaay up there over 135 ! And on bias ply tires....I have NO idea why I am still alive....... :shock: :shock: :shock: :shock: :shock: :shock: