Hello. I have a 1984 vanagon and will be installing a 1998 subaru 2.2 engine in it. I chose the 2.2 because I have a 1997 Legacy and a 1998 Impeza as parts vehicles. Both engine are in good running condition but I plan to use the !998 Impeza engine because it has lower miles. I plan to rebuild the engine completely and am looking for any ideas for performance improvements. I am aware that this single port engine was only used for two years and am finding that some parts such as pistons are difficult to find. Any ideas would be greatly appreciated. Thanks 

If it runs fine, do the seals valve cover, cam & crank, timing belt and oil pump reseal and call it a day.

No need to rebuild.  If it isn't broken don't fix it.  IMHO.  Great engines 300K+ miles and still going strong.

^ agreed. At most, do the head gaskets and move on with the conversion. Definitely do a cam belt kit including all front seals and check the torque on the screws that hold the backing plate on the oil pump. 

Some would say leave the rear main seal, I say replace it while you have easy access. Reseal the air oil separator plate and swap it for a metal one if it’s plastic. 

Enjoy the conversion. It’s a good process to learn about and the result is awesome, I think you’ll love it. 

Cheers 

Bennie

Yes to the above!