Help with bouchillon kick down cable

Thread revival! I'm a B-bodies member, but find great info here on the A-bodies site and check-in occasionally.

I've been running a Bouchillon kickdown setup on my Cope Racing 727 with stage 2 shift kit. I adjusted both the throttle cable and kickdown cable with carb at Wide Open Throttle. I did have it for a while where everything shifted fine, but kickdown only worked if you mashed it to the floor. I'm trying to adjust it so it will kickdown at 3/4 throttle like a modern car. Today I adjusted the kickdown bracket slider so it put a little more tension on the kickdown cable. During the test drive it short shifted 1-2 and 2-3 and then at WOT would not kick down at all. I parked the car and adjusted only the kickdown bracket slider so a little less compression on the slider internal kickdown spring. Drove again, same result. Now I'm just trying to get back to where i started. I sure wish this thing had a ratchet on it. I've been making sharpie marks on the kickdown metal slider for reference. I think I need to clean it off and make numbered hash marks every 1/16".

Any suggestions from someone who's got the Bouchillon setup to kick down at 3/4 throttle? Most of my local mopar buddies are driving manual transmissions. I know it's a careful balancing act with getting BOTH the throttle cable and kickdown cable adjusted correctly. On the kickdown cable, if erring on one side, is it better to have a bit of slack in the visible cable near the carb attachment point or should there be some tension on it? I don't want to burn up my trans.