ring gap

[ebert]

what should I set the gap at on a big block chevy marine closed coolant at 170 degrees. top ring is total seal gapless secong ring is conventional bore size is 4.610 naturally aspirated

[Frankshaft]

With the gapless top, it won't really matter. I would set them at .028-030. in a marine application they will be subject to some extra heat, for prolonged periods of time.