If I expect to keep this truck rolling down the road I am sure a fresh engine is in the works. What the pros and cons be to upgrading to a 5.8?

If I was to do this would I have to change wiring harness or what about ecu?

 

Wow!

 

Pros - more power and low end torque

Cons - different firing order, different exhaust, some other small things.

Mostly its bolt in.

 

Why makes you say the different firing order would be a con?
Would the ecu need to be changed?

 

I think you could just get away changing some plug wires but I am not 100% sure.

 

What is the current engine, year, mileage and running condition.?

 

I believe the engine to be original. I am basing that on what the condition of everything was when I acquired the truck. I am not sure on exact mileage. What it reads is 54918. I do not know if that is 154, 254 or more.

When I first got the truck in 2011, I replaced plugs and wires, and by now I have replaced all ignition. For some reason when I got the plugs for truck, they would not fit. I had to get longer threads. The plugs that are in now are the platinum. Would this cause the truck to run different than designed?

Would a regular plug with the same length threads be better?

I guess the truck doesn't run too bad considering age, just thinking that if I am fixing it up to keep around for another 25 I should go ahead and put in new engine.

 

Generally on these older trucks I stick to regular copper motorcraft plugs and wires. They seem to cause the fewest problems.

I have these same thoughts myself - my truck is going to hit 200,000 miles pretty soon and while the engine runs great, you are always sort of waiting for something bad to happen given its age. So I am keeping my eye out for good deals on engines and when one pops up for a good price I will buy it and then rebuild it when I have the time to learn how to do such things.