The 300 turbos use the vacuum strictly to control the speed of the shift........not the timing of the shift. They have a Bowden cable for that purpose.

The older systems used vacuum to control the speed of the shift and to also delay the shift depending on the vacuum level. They didn't have a Bowden cable.

So, certain older vehicles........240's for sure.......cannot have those valves removed without affecting the transmission performance. I'm really not certain of the years and models that are related to this situation, but I'd presume that for any vehicle without a Bowden cable, it will certainly be applicable.