I have searched this forum all day and have not found all the answers I need.

I have a dead 1997 f150, 2wd, standard trans, 4.2L, standard cab

I want to hopefully get a low mileage engine from a junk yard. If the mileage is low enough i will prolly get the transmission too (mine is becoming harder and harder to shift).

Now, I will beat the dead horse:

What is the best swap? ... I'm looking for the easiest swap possible, exluding putting in another 97 4.2L. I'm not concerned about gaining horsepower, though that would be nice if little additional work is needed.

In all these cases what components could I keep / what would I have to change in regards to stuff like ----> pcm, air flow, exhuast headers, coils, harness, mounts, transmission

'97 4.2L to '98 4.2L
I've heard some 98's still have gasket problems if this is really just a simple drop in I may take the gasket risk.

'97 4.2L to '97 4.6L
The headers would have to be changed, correct? is that simple?
PCM changed too. Would there be any other electrical issues?
mounting issues?

'97 4.2L to '99+ 4.2L
PCM changed, any other electrical issues?
mounting issues?

Please help, truck has been dead for almost a year now, and it's time to fix it. I have to do it at my dad's house so would want a pretty quick job so as not to consume his whole garage for long.

Thanks in advance,

Nathan