If you Googled em I think some good reading would come up. A skim cut would ensure the decks are flat & iirc some 1.88's are a good plan. I have a set I purchased for either 50 or 75 I forget which about 15 years ago. I wanna build a tight quench 318 for a mileage DD. skim cut/new guides/new valves would be completely gone thru (use em & get your moneys' worth out of em). I would home port em especially as I did not realize they were real dogs as is.