Get into a bench-racing session with any hot rodder active during the '60s and don't be surprised if the topic of discussion eventually settles on "those rocket engines they used to sell that bolt to ...

There once was a magic bullet for extra speed. It was a bolt-on device. Bolt it onto your rear axle and you instantly had 1,300 hp at the press of a button. Magic, right? The 130-pound device was ...