will a 1997 f150 5.4 fit in a 2000 f150 with a5.4

 

Yes

 

It will but you will be down on power. The 97 has non-pi heads and the 2000 had the pi heads. These were good for about 30 hp more on the 2000. However, if you take the pi heads and mount them on the 97 engine you will net close to 290 hp iirc. Look up "pi head swap" if you want more info.

 

The front cyl head sensors are different, so you will have to adapt for that. 97 has 2, 2000 has only one.

 

Technically illegal.

Engines, computers , and emission control system combinations are tested by mfg and certified by EPA

You must replace with a certified system of same model year or newer

Unless its for offroad use only. These are federal laws.

Some states arent strict with testing and inspection.
Some are.
California is the poster child .

If yours does tailpipe testing, thats a good indication.

The years with Pi heads might be interchanged unnoticed since probably no real engine changes

 

Wow that makes me happy to live in a non nanny state