http://www.musclecaroftheweek.com - The "K" in the 5th VIN position has special meaning to early Mustang fans, and this 1966 version is a perfect example of why! The K code cars featured not only the 271 HP 289 V8, they also rode on a performance suspension system. We take a look at a Signal Flare Red K-Code from the Brothers Collection to learn more.