Gentlemen, I have the 29440-99B S.E. air cleaner on my '06 CUSE. And it is true that the outboard or top rubber gasket does not seal 100% with the stock S.E. cover. This is do to the tapered shape and the embossing of the cover. But the filter element does not draw from the top side, it draws the air in around the circumference. So the top or outer rubber gasket does not function as a "seal" it just holds the cover in place (so it does not spin)if it is a stock TC88 or an S.E. cover. I have the same air cleaner on my '02 RK, I'll check to see if there is a 100% contact or seal with that cover, given the rounded shape of the TC88 cover both front to back and up and down I have to question if it seals 100%. "Ride safe" 8-)