Tri-power Linkage - SBF

[jefeingold]

I have an August 1964 Buddy Bar/Ford Performance manifold with the correct Holley 2300 two-barrel List 2867 and 2868 carbs and the proper linkages.

The problem is that if I get the carbs all opening at WOT in synch, the secondary carbs begin to open at about 20% throttle in the primary. If I adjust the linkage to get the secondaries opening at the desired 40-50% of primary throttle, the secondaries don't reach WOT. I can't find a sweet spot where the secondaries open at 40-50% primary, and still all reach WOT at the same time. It's making me crazy.

Any suggestions?