Is replacining the engine worth it?

[a98kdoc]

Try this.
Pull the spark plugs and look for scarring on the pistons. Harbor freight sells a fiber optic camera video gizmo cheap you can put that down the spark plug holes.
If the piston soot has valve like rings hammed into it you need to do a valve job at least.
If not Have "Rorl" do the work tell him you are a member and he will charge 2x. ( I would )
Also at 200K look up all the maintenance that needs to be done and I would go for a transmission at the same time as well.