Having a little trouble finding a rebuild kit for a throttle body from an 89 Chevy C3500 with a 454. The Chevy dealer said it was discontinued. NAPA is showing one, but from the picture, it doesn't look right.

I don't understand where the gaskets with the one big hole would be used. This is a 2 barrel throttle body. I have to order it, and it is like $45, and I can't return it, so I'm trying to be sure. Next step is to start tearing this one apart and see if I find anything that looks like the parts in the picture I guess.
Anybody have any kit numbers or sources?[/img]