She won't start

1983 Ford E150 302 econoline. She is a retired airforce surplus van, been through alot. Well the other day decided to do a tune up on her and my son (15) pulled all the plug wires at the same time. I have what seems to be the right firing order 15426378 but still no luck at getting her started. Have been working for three days now ready to scream. If anyone has any ideas of what i am not doing that I should be PLEASE let me know. I am at my wits end.

how did you get on the BMW listings??? anyway is there spark at the plugs, are you getting gas?? if yes to both of the question then check the firing order again..