GM-GMC: 86 GMC turns over but wont start sometimes, throttle body, fuel pump

Question
I have a 86 GMC 2500 4x4 with 350TBI with a automatic.  Sometimes when the truck is cold it will turn over good but will not start.  If I leave it alone for a day or so most of the time it will start up.  When it does start it runs great.  When you crank it over for a couple of seconds and stop you will here a click.  When you crank the motor again it will start every time. If you do not here the click after cranking it  the first time, it will not start.  After the truck is started and shut off, it will start up fine.  It only happens after the truck as been sitting for a day or so. It has a new Optimum red top battery so I think it is getting enough power.  Any help would be great.
Thank You

Answer
In order for you to figure out what the problem with your truck is you will need to 'catch it' on a day when it will not start.  Start with the basics.  Fuel then spark.  I would imagine only one of the two will be missing.  Say for example you have no fuel entering your throttle body when cranking, check to see if your fuel pump is running when  you crank the engine, if not running, check both the control side and the power side of the relay etc etc.  
Pick a day when you have some time to devote to it and when it is acting up.  
Hope this helps.