A-904 shift kit

Hey all, I am new to the forum but have been slowly fine tuning my '73 318 dart with a 904. I read where AJ/FormS was writing about how you got it shifting pretty sweet even around corners with part throttle kickdown. I don't have that feature (the PTK) but I am going to install it on my 904 and wanted to pick your brain, if y'all don't mind too much!

First. I hear the PTK works at about 3/4 throttle, is this true? From AJ's note I think he got it down to less than that at low speeds (corners). Can this be done? How?
(I don't want to take apart the governor at this time but if that is the answer so be it.)

I don't know how the part throttle system really works, I know there is a spring in there. I understand this only works at below about 45-50 mph. Is there a way to raise the rpm window for the PTK up to about 60 mph?

I ask because if normal 3-2 kickdown is at full throttle, and ptk is a lt .75 throttle, that is still a lot of pedal in my eyes. How to bring this to half throttle or even 1/3 throttle? Possible?


Next question is, (unrelated) I could use the 2/3 shift (normal operation) a bit later than now, to match my 1/2 shift. I have heard of stiffer springs for 1/2 but not for 2/3. Do they exist? What size are they? (Dimensions)

Also have heard of "shimming" the spring with some washers. Any downsides to that that may damage the trans? (I'm talking lite shimming, not crazy 40 washers stacked up)

Abodiesonly rocks!

Anyway thanks in advance and hope to hear back from y'all!

-Frank