Engine swap for a 97 F250?

I have a 1997 Ford F-250, with the 7.5L 460 (245hp). I want to add a bit of power to it, what mods can I add to the 460 to give it more horsepower, or could I swap it with the mustangs 5.0L coyote V8?

1994 Ford F-250 7.3 Diesel has difficulty starting?

My son has a 1994 Ford F-250 diesel that was running great until about 2 weeks ago. It then begun to have difficulty starting. When cold, it will crank and start most of the time, and it runs just fine after it gets going. But if he drives it and it warms up, then he stops and shuts it off, it won't want to turn over. He is able to put starting fluid in it and it will fire right up, but we know that isn't good for the truck and would prefer not to have to do that. We're trying to figure out the issue and have ruled out the battery, glow plugs and vacuum leaks. Any diesel mechanics out there with a little advice what to look at next? My son is thinking the fuel injector pump, but I'd really hate to spend $700 on the part and be going in the wrong direction.