seeing is that your kit is "custom" what exhaust manifold are you using and how low do is position the turbo in reference to the oil pan? it could be sitting too paralell and not drainng properly. also like cronic said, oil outlet size, i use 5/8 steel braided and havent had much luck with anything less than 5/8. is the return line pinched in any way? and last but not least have you clocked the turbo and are you sure you have the "oil inlet" and not the "oil outlet" a friend of mine did this too