TH-350 parts

I picked up a Jeep truck with a 3.8 buick ans a th-350. I want to put a adjustable vaccum modulator in the trans I was told to ask for the "red stripe" modulator. all the parts guys in my county look at me like i'm crazy when I ask them, Maby I am but does any one have a part number that I can give one of these slacks so I can get the right part? I can not expect one of these guys to open a parts book, I'm not sure they know how to turn a page only kilck a mouse and make me the Idiot. Am I an Idiot? latter, rob
P.S. any good parts links for older cars?

 

the red stripe means it is adjustable an extra wide range..try napa part # ATP 17499