no I did drain the oil, just did not want to use the studs that came with the URD kit, and finding new studs was hard, so I used bolts instead of the URD studs, the studs from URD were cut and rethreaded, and the threads look shallow. My fear of using the URD studs were cranking them in and stripping the pumkin, using the new bolts and one new header stud (just long enuff) lets me sleep better at night, and not finding a leak on the ground... (Now in NO way em I telling guys to do it this way, its just the way I wanted to fly go, EZ)