Do It Once, And Do It Right. Take Brent And Rorys Advice And Get It Milled So The Surfaces Are Even. It Doesn't Cost That Much, Especially With The Cost Of Multiple Gaskets, The Cost Of Oil That Will Inevitably Leak And Need To Be Topped Off, Degreaser For Your Garage Floor Or Driveway, The Ridicule Of Your Friends Over Your 1/4" Thick Stack Of Leaking Cork Oil Pan Gaskets, Or Front Seal Slinging Oil All Over Your Other Expensive Engine Parts And Engine Bay, ETC , And, Eventually Having To Tear It Apart And Do It Over The Right Way. FE Doesnt Stand For "Cheap Out" If You Dont Have Tooling Like Brent Described, Do Some Measuring, And Make A Spacer To Center Up The Housing, Without The Seal Installed To The Crank. Also, Be Sure The Seal Is Installed From The Correct Direction. Mentioning That It Is Aftermarket Means There Are Possibilities It Is Not The Same As A Factory Cover. Good Luck, And Do Both You And Your Engine Proud...Do It Once And Do It Right!