what is the peice that comes up out of the valve cover and is a elbow that bends to the left witha hose coming off it? and how important is it to my truck? and what happens if i broke that? any help?

 

Most likely a PCV or vacuum line. Important either way.

 

it is most likely from the under side of the air cleaner feeding the front of the valve cover just behind the oil fill cap. part of the PCV system

 

essentially, the air cleaner is also doubling as an oil breather. the pcv valve is stuck in side the rear center of your valve cover and connects down to the intake somewhere.

 

pcv valve isin the back, the rubber hose in the front is just a breather you should replace them either way

 

im having a simelar issue i have a breather filter on this port and am tryng to find out if this creates a vaccume leak.see lots of people rumnning just a filter
and lots of people running it to the intake.i am currently running a filter
scratching my head on trynig to put a hose on it to the intake

 

As stated, if it's the back one it's the PCV. Replace it. If it's the front one, it's the crankcase vent, replace it. If you have a weber carb and there is nowhere on it to attach that front hose, put a filter on it instead so you aren't sucking dirt/water etc. in there.