I have begun the rebuilding of the 4.2 engine from my 77 CJ-7 barn find project. My local NAPA store in Buckeye, AZ has a reputable engine shop attached and run by an family friend of my wife. Its good to have friends with years of experience to help. I opted for NAPA's deluxe master  rebuild kit which is a good value when you get it all at once. I was pleased with how clean the hot tank process got my dirty block and sheet metal. I had given up on scrubbing and even the pressure wash