Have 1964 Comet K code. At a crossroads. Keep it, sell it... Saw a post with 64 that had radiused wheel wells. Great idea. Getting r tires out is bitch. Looking to talk with Comet guys. 64 in particular. Will post pic very soon
Keep in mind that the Mercury "K" code is different than the Ford "K" code. Mercury 1964 "K" code is 289/210 horsepower. Not the Ford 289/271 Hi-Po.
I used to own a '64 Comet 'K' code... Four-speed/bench seat Caliente hardtop. One I sometimes regret selling... As was mentioned, it's not a hi-po motor, basically the same as the Ford 'D' code. Mercury did build a handful (10-12) of specially-equipped 289/271HP '64 Comets for a sales promotion, but those used a 'D' engine code (for Daytona, which is where they were used) and only a few exist today, so go figure... While it's based on the Falcon, it was actually the source for most of the early Mustang bits (rear suspension, a lot of interior trim bits are the same as Mustang). Better ride quality and roomier than the Falcon, but finding some parts can be a bitch; lots of one-year-only bits on them. Delta Bay Mustang sells a Falcon/Comet-specific strut tower brace and lower crossmember that will noticeably improve handling.
1964 Comets had a 5.5" longer wheelbase and were 13" longer than a Falcon which may attribute to a better ride...