1988 Honda Accord

Hello all, My daily driver is a 1988 Honda accord 2.0 5spd. She runs great now… I am on my 3rd transmission and have done alot of work on the car in general. Mostly routine stuff to keep it on the road. I had a recent scare driving the car. Long story short the cam gear had come loose and as you can figure it ran terrible. After fixing the problem I realized that the engine is REALLY sludged up. my mechanic friend said the car was not long for this world. My question to you is there any way to correct this without a rebuild? The car has 260K on it and my commute is 85 miles one way. If I have to replace the car. What years and makes/ models do you recommend? Im a sucker for a 5spd that is a must. I also want to be able to work on the car as I do all my vehicles. Your opinions are greatly appreciated. Thanks in advance, Robert