We stopped using BP years ago. A lot of the Engines that come in for freshen ups that run BP have worn rocker shafts and Piston Pins. We only use Driven Brand Oil, every Big Block we Dyno has BR50 in it. In a lot of our high HP Drag engine we use XP3 after dyno but in most cases the HR series oil is a good choice. We use the 15/50 in our bracket style engines.