I'm not sure if something is machined wrong with the block or if it is still blowby that is causing the leak.
There might be , I remember back around the time we did the Enginemasters challenge that Dan (member PerformanceOnly) was telling me about a rear main seal leak he had on one of his customers build , it was a member here I think, that ended up being the rear main seal bore or cap being slightly off set in the block ... the only way to see it was to have the crank out though .
