Part throttle kickdown setup.

I am building a 904/999 geared tranny for a mild street 318. I am on the hunt for the correct kickdown parts that are used on the valve body.

All of the ones that I have are the type that have some aluminum sandwiched between the valve body and a steel plate. IIRC the one I want is a single aluminum casting.

I got a couple of questions:
Will the single piece kickdown assembly work on any valve body and transmission?

Does anybody know of a vendor that sells the correct stuff?

Thanks.