The last of the fire breathing big block Cougars were built in 1971. They featured the 429 Cobra Jet engine, and carried one of the highest factory horsepower ratings (370!) of any Cougar ever built. Sadly the times were not right and only a handful were built. The '71 Cobra Jet Registry is maintained by Mitch Lewis.
Mitch,
I have been trying to contact you for several years now. I have a 71 429CJ Conv. You may already know about it, but I would like to be sure.