62mm BBK
I bought cheap a tb and screwed around with it and the stock one.
I installed wide open throttle blade positioners but the comp didn't like it and would 'wrench it', hooked up the SCT reset the code and drove it home. I did this several times first with 62 then the 55 figuring out the comp didn't like being told where absolute wide open (blade 90* to body surface) so I removed them.
I also messed with the adjustment screw on the BBK which is brass but Not the stock plastic one. On the BBK there is a small setscrew that hold's the adj. screw located under the actuator cover that you can back out and easily turn the adj. screw. I also tried different springs and reinstalled the stock one in the BBK adjusting the spring tension as I had removed the snap ring and lost it and the slug so I just tapped 1/4-28 or 5/16-24 and used a hex set screw that can adjust the tension, I also have a half-nut to tighten down and hold this setscrew.
I adjusted the big brass adj. screw on the BBK so that by depressing the plunger end I then adjusted the big screw for throttle blade closed opening that I wanted. The spring actually opens/keeps open the throttle blades and the actuator controls the total movement/throttle position via the comp.
I have driven it considerable miles since. I think I have lighter preload on the small one than it came with, not much though.
I just looked at my stock 55 tb and there is not a setscrew to there must be locktite used to retain in place. Maybe you could buy an adj screw from BBK (ya right) after getting it out. I think drilling very carefully and then using a tap clean out the threads and insert the BBK one!!!
