What do you not understand about the RPM targets of the governors? There are 7 different ones that go from 5,000 to 6,000+ RPM. The biggest issue with changing governors is that a shift split will usually come along, too. In other words, the 1-2 will happen at a slightly different RPM than the 2-3. The spread will be greater with increased line pressure and also increases with each higher shifting governor. This can be somewhat corrected with A&A's spring kit. BUT! They are not exact and require the valve body to be removed and disassembled to install them. It can take several tries to get as close as possible, but often will never be exact and can even change with fluid temp.

What RPM are you going for?