The last untouched 69 block I did was that way, 1 side perfect, other .001 low in front, .004 high in back. I used same rod and piston in each hole, wrote my measurements in valley and had it milled. All .001 in hole when done, started .017 or more. I was also going to leave it but wanted that .040 quench for the closed chamber heads. If I get around to it mocking another 1970 today, be interesting to see where its at. Its a winter project but with machine shop wait may take that long...