With the way gas prices are going (down for now, but the market found its honey and it'll go back up to $4.27 for 87 octane again), and if you plan on using the 4x4 drive much you might be just as happy as stealing the huge diesel engine out of a 89 ford f250. You already said you will be doing alot of 4X4 on weekends. My friend has a stock one, does plenty of driving, rarely refuels and doesnt bust his wallet at the pump Hell, he doesnt even need 1st or 2nd gear. These guys are telling you to go for torque with the 390, so why not go for torque with a diesel instead. You could even throw a turbo on it and increase power and mpg, or just do the normal, easy mods to the stock diesel engine (upwards of 7 liters). In the long run, heading to the junkyard and finding the huge diesel might make you happier in the long run. Save that 390 for a future project.

Hoping I dont seem like an idiot, just an army mechanic by trade and a hobbiest mechanic in my off time. For a truck I honnestly think that you would be happier going this route, just make sure you have a STANDARD transmission behind that engine.

What do you guys think? We're all FE fans here, but ask yourselves if it would be better for him going my way or yours.