Originally Posted by superHEAVYfunk
I'd imagine that even if the two were physically compatible, you'd find yourself having intonation/tuning issues because of the different scale lengths - the frets wouldn't be in the right places.
That all depends on where the bridge is located compared to the neck pocket right now. But, you're probably right. The intonation would be screwy & not a proper 34" scale with the bridge in its current spot. It's much more likely that fender would move the bridge up and keep the neck at 20 frets than to cut frets off & leave the bridge in the traditional position.
If he were to swap the neck, it would be best to measure the proper distance to where the bridge SHOULD be, and move the bridge accordingly.