What are the benefits of installing a complete Transgo shift kit, which includes the .500 boost valve and the corvette servo, over only installing the boost valve and servo?

 

The timing of the shifts will be off some if you don't install the whole kit. You need to drill out the clutch release holes so that 2nd can release as fast as 3rd applies as an example. Down shifts are even harder to get right.
This is just what I've figured out from calling many tech lines and asking lots of questions and tons of net searchs.
All I know is, the whole oil system is balanced. If you change one thing, it will probably screw something else up.