You only use a 528T on a 1.6gpf Gmax toilet. On a 1.28gpf Drake (CST744ES, for example), it will overfill the bowl. That you have a green fill valve suggests that at least one of your Drakes is the 1.28gpf model.
You want the Korky 528MP (528MPK on the Lowe's web site) Maxperformance fill valve. This one, with the silver cap. http://www.lowes.com/pd_336988-868-5...3284948&rpp=32 The reason you want this one is that the refill percentage is adjustable. On the 1.6gpf Drake, to fill the bowl uses a fill valve set to 40% refill ratio. (Refill ratio is the percent of water coming out of the wall that goes to refill the bowl [through that refill hose] as opposed to filling the tank.) On the 1.28gpf Drake, the proper refill ratio is about 28%. This valve will work in either one, or any other Toto toilet, because you will quickly learn to set the refill ratio to the proper amount. There is a video on how to install it at: http://www.youtube.com/watch?v=Gw7HvHtaA84
Come back with any other questions.