i am not a machinist, having said that. 3.875 is standard bore. 3.875 +.060 = 3.935. if your biggest hole is 3.925 then there is room to go to .060 . granted i do know it is hard to set up a boring bar for just .005 over like what is needed in # 1 cyl. i would not take it past 60 thou for street use. tom

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