i bought the bung from stan... should i drill a bigger hole and weld it in through the back, or drill a smaller hole and weld it straight on the outside?

 

not exactly sure what u mean through the back or striaght, but the smart thing would be to make the hole bigger to flow better and as high as possible for less chance of the oil to back up into the line. i blew my turbo last month cause i added too much oil

 

I drilled the hole to the same size as the fitting and welded it onto the outside of the pan. That's it.