I tried an aftermarket drain plug initially, but was not very impressed. It didn't seal as well, and was a PITA to remove/install due to exhaust pipe clearance issues. So I broke down and drilled the stock part. I thought for sure that I'd screw it up, but everything worked out OK. You can't tell in this pic, but I drilled it in three spots just to make sure I'd have a hole where I needed it, depending on my safety wiring creative juices at any given time.