I have the factory 81 service manual, any my hood diagrams are FUBAR. It has an A/C section in the book, but it doesnt show you crap besides, this is what this valve looks like, this is where the components go, and this is how you take apart the compressor to the last little tiny screw! but no vac diagram! the main emissions one doesnt have that VSV on the picture, its strictly for A/C.