I just measured the end gap in my megablock with new unfilled Total Seal 4.505 rings. My bore is now 4.5043 so I was wondering how much more room there would be before the rings would have too much end gap.
With a new 4.505 ring measured in the 4.5043 bore the end gap was .010. Using .0225 as a proper end gap for NA apps, that would allow a bore of 4.5082 and still be at .0225 end gap. I am not sure what effect the extra crevice volume would have on an alky motor, but if it isn't too much , coating pistons to take up all that extra bore space would allow a lot of rehones and rerings. It cost me $300 to have line2line coat my pistons. That is a it cheaper than a rebore and new pistons!