Had the motor all back together. Nose bowl and cowl on. Noticed an oil drip. Funny since there isn't anything more than residual oil in the engine. Wiped it off. The next day I found another drop. I traced it to one bolt in the sump. Re-torqued it. Another drip a few hours later. Removed the bolt. It was tight. Ran a bottom tap in the hole and came out with gasket material. Odd. Lycoming sump gaskets stick out of the flange a little in back but this one had a little extra on the right side. I couldn't sleep for thinking about it. Ordered new sump, exhaust, and intake gaskets from Spruce while drinking coffee this morning. Picked them up this afternoon. Removed the cowl, nose bowl, and cowl channels. Disconnected the servo lines and cables, removed exhaust, removed intakes, and dropped the sump. Good thing. The bolt was leaking from not torquing because the hole was fouled with gasket material. The rear part of the gasket had slid and that was the only bolt that suffered but the oil pickup gallery was at least 50% blocked. One evening lost to retracing my steps for a stupid mistake. Sometimes it pays to listen to that internal voice.