diwells

My husband and I have been working on this wagon for about 4 years on and off. We had the engine evaluated by a Subaru mechanic who said it was in great shape. There have been other problems, but the engine was great until we lost compression in one head. We replaced it and now can't get the engine to stop missing sporadically. The engine has 162,443 miles on it. Compression seems fine. I've cleaned the spark plugs. Should I reset the gap? Get hotter spark plugs? Clean the distributor rotor again? Even with the occasional missed spark this car gets about 35 MPG, slightly better than our 2008 Honda Civic. My husband, who has done all the grunt work on this car, wants to donate it to charity (i.e. for scrap). The body is rust-free with only minor dents/scratches and a clean interior. I'm tired of working on it too, but would like to get it running well and find a new home for it out of the scrap heap. Any suggestions will be welcome.