Thermostat Housing

[rgforge]

Howdy Fellow BowTie Disciples,

I have to start out apologizing for my ignorance. I grew up around Chevy trucks (my Grandfather's femur was in the shape of a Chevy bowtie!!! J/K!!! He was a BIG Chevy man). I have a 1986 C30 Silverado Camper Special 4 door dually with a 454, th400, and a western hauler bed. I have been trying to line this thing out. It runs but not perfect. This has always been a dream of mine to have one of these Chevys and fix it up. I went out tonight to replace the EGR valve. I noticed that most of the vacuum hoses were cracked, split, or broken. While working on the EGR valve, I moved a hose and noticed 3 or 4 hoses in a broken piece, cylinder shaped. After looking around, it seemed to have broken off the thermostat housing. I am assuming that houses the thermostat since the upper radiator hose goes into it. I am looking in the Haynes manual and can't find anything. What is this part called so I can get it at the parts store? How important is it? I would assume important since it interferes with the vacuum system. Would anyone know a good resource for a vacuum hose diagram? I apologize for any rookie, greenhorn questions. Thanks for the help.

Robert

Edit: This truck has the Smog package on it. Would love to take off, but don't have a clue on where to start.