GM-GMC: timing, chevy astro van, chevy astro

Question
I have a 91 chevy astro van 4.3 z tbi . Whats the timing degree it has to be set to ?

Answer
With the timing advance wire unplugged, (usually a tan wire under located in or under the glove box area) the timming is 0 degrees before tdc.... when lifting the hood of your truck just on top of the rad or on the underside of your hood.  There should be a sticker that indicates the size of your motor and so on... the ignition timming should be writen there.
Hope this helps