when drilling holes at the top of the pistons (compression pushes rings outward for a better seal)what size hole and do you drill down to the second ring also or just the top ring

.040-.050 dia You want to drill them at an angle but if this is your first time drill them vertical.You want to hit the back of the ring land .Measure piston dia and ring land dia.Us the quill stop and move it 1/4 turn per poke or uall have some broken drills in your holes.Buy 1 drill for every 5 holes to be safe.dont wait till one gets dull.Or youll push a burr in the ring land and or break a drill that costs less than a buck or two.Use Cobolt drill not cheap HSS

You should always think of the rings like this. The top ring is compression, the second is a scraper and the third basically oils your wristpin. If compression gets past the top ring, it's best that it gets past the second ring too because if pressure gets between the top and second rings, the top ring will become unseated and will basically be along for the ride only. My point being, only drill to the top ring groove.

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If compression gets past the top ring, it's best that it gets past the second ring too because if pressure gets between the top and second rings, the top ring will become unseated and will basically be along for the ride only.

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this is why sealed power recommends opening up the second ring gap