By Original Cobras I would guess you are counting the CSX, COX, and COBs all. The CSX Cobras were built here in Los Angles but the bodies and original chassis came from Thames Dutton I believe it was. They used to race them as AC/Bristol and for some reason Bristol quit making engines for them. So AC wound up with a bunch o0f bodies and no engines. Ford had just came out with their 221 CI. and Shelby decided to see if one would work in the AC Body. They flew one with a 4 speed to England, put it in a car and tested it. They then removed the engine and transmission and brought them back here and had the bodies and chassis shipped over. By the time they got to making them Ford had moved the 221 CI engine up to 289 and that is the ones that you hear about first.
Ron
