Welcome to the starter replacement club.

Your idle problem started when you cleaned the pcv oil separator, your now pulling crankcase fumes through the plenum. So now what you have to check is the idle air control valve (solenoid) to make sure the plenum's seat and iacv's metal cone are free of carbon. Reinstall when clean and pray the idle falls back to 650/700. If not you may need a new iacv and an ecu reset by a garage.

Good luck, your about to find 99% of all Disco issues in short order I guess.

 

One other thing......

The big end and con rod shells.....when you ran it dry they lost a little skin. I know you haven't been inside a motor and you already had the pan off but I would have put eyeballs on them and measured bearing thicknesses. You probably are down to copper. The big problem with these motors and most don't realize it but spinning a crank bearing is the number one pita problem because finding a usable crank to turn (and you have to true the journals afterwards) is nearly impossible.....they warp beyond spec and are scrap.