FEL-PRO and SCE make one piece gaskets. No Sealant is required and they are re-usable. I put one on my 351W and haven't had any drips. $30.00 as opposed to a $10.00 four piece. The FEL-PRO comes with four of these slick 5/16 threaded plastic screws that hold the gasket up on the block and just make putting the pan back on eaiser.
You might want to check the
oil pump's "pickup" assembly and make sure you have it set at the correct depth.