Firing Order for a 340

I have a 340 engine in a 76 Plymouth Duster and I am having trouble getting the engine to fire. I have replaced pretty much everything electrical under the hood, but I am thinking I may have the spark plug wires in the wrong firing order on the distributor. I used a diagram online to tell me the firing order. It says 1-8-4-3-6-5-7-2. Is that the correct order and if it is, what are common problems that cause the engine not to fire, but will turn over? Thank you!