And before Richard shows up singing the Brit tune, the AC Ace was indeed the base (rhyming here) but it underwent more than just a little modification. The frame wass reworked and triangulated and a somewhat diffwerent rear end design went in. Mods to front end and the entire suspension system with nylon bushings etc., produced a much better handler to go with the Ford power. The racing Cobras came into their own when Shelby, who knew talent when he saw it, hired Peter Brock to streamline the car and develop the coupe version. On the tracks, this was the real killer version of the Cobra.
On the street the 427 roadster was a serious ground pounder but the extra weight of the big block Ford took away its lightness and what little nimble handling it had. But that fucker would light your eyeballs up. The same was true of the Vette's of the era. The small blocks when properly set up were fairly good road racers but the big rat motor versions were straight line only but they too made you gasp for breath.
Dropping the hammer on any of the muscle cars from that time was something and never forgotten for those of us with gasoline for blood. There are new cars far quicker but the beauty of that rumbling roar, the rattling from the vibration, and the pull of the engine torque..............yeah.......Wish I still had one to play with if just for awhile.................