valley pan not sealing and drawing oil into the head intake port(s). I'd pull it & clean the head/intake port faces & I'd probably go ahead & get a new valley pan & if you used a new one when you painted everything I'd possibly reuse it & carefully clean the port opening area(s) on that one & my preference is to coat each of the 8 port openings in the pan on both sides with a LIGHT/EVEN coat of Permatex #1 in the toothpaste like tube (thick/viscous/seals well) with an iron intake and Permatex #2 if an aluminum intake