How do i set the points on my 1977 GMC chevy sierra?

I recently changed all the spark plugs and wires, rotor cap,and a new thing that needs the points set. Now the truck ran before i did all that, could it be that it doesnt run because the points are not set? I dont know that much about trucks so , what feeler gauge should i use or shall i say what points do i set them at?.......Now i do know the arm moves horizontal and you use an allen wrench to set it i think...PLEASE GIVE ANSWERS IN YOUR SIMPLEST EXPLANATION ON HOW TO DO THAT AND IF THAT IS THE REASON WHY IT DOESNT START UP ......it does turn over but it just wont catch sparkHow do i set the points on my 1977 GMC chevy sierra?Your 1977 P/U does not have a point distributor unless someone have changed it.

It has a HEI type distributor with the coil mounted in the cap.



If you are not getting spark check



1. On the front side of the cap there is a 3 wire plug closest to the cap. The outer terminals are marked BAT %26amp; TACH



2. Remove the BAT wire %26amp; Check for continuity



3. If there is power [with the key on] Then remove the cap.



4. Inspect the condition of rotor, cap, %26amp; center electrode.



5. If checks OK remove the module mounted to the base plate



6. Inspect the wires for overheating or corrosion.



7. If the module is original, replace it.



8. With an Ohm meter check the continuity of the pickup coil.



9. If checks OK remove the HEI coil from the cap %26amp; check continuity.



10. Buy a manual if unsure how to perform these procedures



- - -How do i set the points on my 1977 GMC chevy sierra?Make sure you have the firing order correct from the cap to the plugs. The points are set to a certain gap. You will have to find out what gap that is for your particular vehicle. As the rotor turns, you'll notice the points close and open. On the closed part is where you'll set the gap.How do i set the points on my 1977 GMC chevy sierra?i had a gmc once and its hard to get a feelers guage in those kinds that takes a allen wrench.if the points are not opening up and closing,you wont get spark.ok. turn the engine over by hand,until the points are on the high edge on the rubbing cam on the distributer shaft,then take a allen wrench and turn the points,until you think its looks like about 0.17 thousands and start your truck,now open the little window in the cap and take the allen wrench and turn the points,1 way the engine will almost shut the engine down and the other way,you will lose power,put it in the middle ways.that will work,until you get a meter put on it.How do i set the points on my 1977 GMC chevy sierra?a 1977 any vehicle should not have points. electronic ignition started in the last half of 1974. but if you do have points in this truck it's an older engine. if you don't have a point gauge you can use a matchbook cover to set your points. install the points,bump the ignition til one of the distr.shaft lobes open the points insert gauge .017 thous. loosen screw ,close points te meet gauge,tighten screw and your done. put rotor and cap back on. start engine