The fitting for the oil drain hose was threaded into a hole on the side of the oil pan. The Vortech-supplied 9/16-inch drill bit was used to drill the final hole. The new 3/8-inch hole was greased and then threaded. The area was cleaned, and the supplied sealer was applied to the elbow before it was installed.
2001 GMC Yukon Vortech Supercharger Installation - Part II