The round track racers I run with use a slave cylinder/throwout bearing that mounts on the transmission nose, similar to late-model Blue Oval transmissions. All that's necessary to complete the clutch hookup is a correct-size master cylinder, and a high-pressure flex line. Pricey, but better than a home-fabricated mechanical linkage! Try Racer's Wholesale, or one of the other roundtrack parts suppliers for a listing.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!