A 700R4 has no vacuum modulator either !--so the VRV valve wouldn't be needed ,period!.....(they are also listing it on E-bay as a "vacuum modulator valve",which is incorrect--that is the "can" that goes on the tranny,the valve's proper name is "Vacuum Regulator Valve"..(or VRV for short)..
That is probably why I did not see any listed when I typed in the right name for it on E-bay back when my TH400 wasn't shifting right due to the vaccum pump pod dying (my VRV valve still works,but I bet its worn inside)..
A cable operated modulator would probably work better in the end,but nothing is perfect--cables can eff up too,though ones GM uses like on the throttle,usually last the life of the vehicle in most cases..that said,for $300,I wont be in the market for one!..