Here's a tip that will hopefully save a lot of headache for some. I had to learn the hard way and totally disassemble a completed concours 428 Shelby. There is a new FE oil pan (repro) that is very nice looking and much needed. After running the fresh engine with one of these installed I noticed an oil leak. After totally disassembling it I discoveedr that the flange although straight is not formed at a true 90 degrees. When you put the pan upside down on a true flat surface you see the inside edge of the flange contacts the surface but the outside edge doesn't and in some places is almost an 1/8" off. The fix is fairly simple, just tap with a scrap 2 x 4 and hammer on flat surface but it is a nightmare if you don't do it before installing on engine.
