Rwillia4 Before you pull valve covers, check out the basics of spark and injector pulse at all cylinders. Make sure that the distributor cap and rotor are OK. Check the center contact for being there. Pull the valve covers after doing this first. I would ALSO call Keith and ask what he wants you to do next?? Did it sound like you lost 1 cylinder or the whole bank went? It's funny that some motors will run on just 4 cylinders. What was the
oil pressure in the motor if you got it to start? DON'T run the motor more than 10-15 seconds. If no or low
oil pressure, it's internal like a lifter out of a bore or pushrod damage. If pressure is good, fine out which cylinder or cylinders are causing the problem. Again call Keith. You don't want to go from a minor issue to a major destruction problem. Get some guys to help you with these basic checks. 6 eyes are better than 2 sometimes. Get a spark tester and a Noide light to check injector pulse. These are 2 good tools to keep in the tool box for future overnight trips. You can also write them off on taxes too.
Rick L. Ps if the motor is backfiring when coasting down, it's either a burnt out gasket or a timing issue. If the gasket is blown you will feel it at idle with an air noise. Another tool you may want is a stethoscope. They are great for finding noises and hear sounds and locating them without lossing a finger, ear drum or eye. Just the hose will help you find any air leaks going into or out of the motor.