A-904 shift kit

In a TF-2 kit, which allows automatic upshifts in Drive;
If the rear end ratio, and the governor, and the engine, are a matched set, then the KD system can usually be adjusted to get a comfortable upshift. These three are intimately related. But if any one of them (and especially the rear gear ratio) is not original or original-type, then they may get out of sync. Also driver preference may come into play, as well as useage.
If you have experience with the tranny before the shift kit goes in, you may already know if it is acceptable or not.
Cranking up the line pressure is a standard thing with a kit, and this will,by itself,delay the automatic upshift speeds. Changing rear ratios will also change upshifts speeds. Sometimes the two conspire to make the automatic upshift speeds too high, or too early, and it becomes annoying.Sometimes the auto downshift speeds get annoying. When these types of things present themselves, that's when a governor mod may be necessary.
I had a more or less stock 73 teener, and a matching tranny with a TF-2 kit and a 2400 TC. It came out of my dying Dart beaker, with a 2.76 rear.When I installed the teener/904 into my S for a winter combo, I installed a 3.55 behind it. And immediately the shifts went out of sync for my driving style and useage. I had to mod the governor twice,to suit me; once to swap out the weight, and once again to fine-tune the spring. It is a bit of a pita to do in-car, but the results were well worth it.