Tuning questions?

[1986Silverado]

I am trying to get my truck running in tip top shape with what I have and have some questions......
1)What is the factory spec for idle speed? I just read 800 rpm in park...is that right? Seems high to me as I have mine set around 650 rpm in park, and that may be part of my problem
2)What is the factory spec for timing? Autozone states 4* BTDC...that seems a little low to me
3)How do I tune an edelbrock 1405 carb?
I tried tuning the carb yesterday with a vacuum guage following some instructions on a web page that somebody had linked in a thread on here, and I seem to make it worse. Gas smell is more noticeable now. Also when I cranked it this morning I had to keep my foot on the gas pedal to keep it from going dead, never had to do that before I fooled with the carb! Another
thing I noticed is after I got thru "adjusting" the carb, when I pulled the hose off of the pcv port on the carb it went dead......is it suppose to do that?