During the 1960s, Ford and Mercury dealers offered many performance related parts and kits. These could be bought through your local Ford or Mercury dealer of from Shelby American. Today, these parts are rare and quite expensive.
Parts for the small block engines, 221, 260 and 289, engines were called Cobra Kits. Parts for the big block, 352, 390, 406 and 427, engines were called High Performance kits.
Since I am a pack rat, I kept my Hot Rod, Motor Trend, etc. magazines from the 1950s and 1960s. Recently, I was looking through some of them and found a number of ads for Cobra and Hi Performance parts. The following are those ads. Check out the prices; I wonder what they would cost now?
By the way, if any of you have the original sales brochures for Cobra parts and would be willing to scan them, I would be happy to add them to this page. Send them to me at doug@jumpthegun.com. I was in the Ford Archives a while ago and was looking at the original Cobra sales brochures that they have. Unfortunately, they will not part with them.