[SS427]

The flat section on the flange ring is to clear the A/C unit on Chevelles. The flared section of the ring will go in the rear and corresponds with the indented area of the air cleaner which is for distributor clearance. Also that is where the "rear" decal is. The flat section would be in about the 10 thru 11 position on the clock. Hard to see in this photo but you can see where the rubber seal is out of round in that area due to the flat spot in the ring. Most people say the tape seam should be in above the "rear" decal but I have found them all over the place and I will normally put them exactly how I found them if it is the original seal and ring.