So today I picked my son up from school, swung by Napa to get a couple bolts. Driving up to a stop light in third gear about 30mph I let off of the gas and the compression braking kicked in (it is a '77 k5, 350ci with a sm465/205) the truck died. So there I am stuck in the right lane of the road. I then pushed the k5 over to access the situation. After numerous attempts of starting it, it would not fire. I called a buddy and he towed me home. The first thing I did was pulled the plugs to see if they were fouled and they all looked fine. I then checked for spark, nothing, no spark. All my fuses are good. The battery wire going into the coil has power going to through it as well as the tach terminal. What is the proper way to test a coil? Is there anyway that with the compression braking the timing chain would have skipped a tooth or two? The rotor still turns.