Glenn has jogged my memory with the backfire story.. Leaving the downtown area of New Bedford is a down hill stretch of 4 or 5 blocks. My buddy had a 64 Impala, I6, we would do the same thing, kill the ignition and tap the pedal a couple times then hit the ignition back on and POW! Watch all the ol' ladies jump and we'd howl like 10 year olds.... had the same results too. Blew that muffler wide open!