68 ford f100 won't start?

the motor needs three things air fuel and spark . I had rust in my fuel tank so you can clean it then coat the insides ,note there is no filter in the tank. Most newer gas tanks have some type of filter in them. If you get a new one make sure it has a filter in it. The ignition point can move .Check to make sure you have 15,000 to 19,000 of an inch gap and that there is no build up on them .Replace if needed. Check spark pluges for buildup ,burning ,gap , burned up end cracked and worn porsulen . Then make sure the wires are good the insides have been know to separate when they get worm if they are carbon wires. I hope this helps good luck.

Another thing you could do is to see if there is anything clogging the fuel filter. My 70 was doing the same thing and I pulled off the fuel filter and it was full of white and green gunk. There was old gas in the tank I didn’t know about and it clogged the filter not letting fuel get to the engine. To fix this you just have to replace the filter and when the truck starts acting up again replace it once more until all of the junk is filtered out of the tank.