Well thats what I was thinking, the Holley kit i got fits a multitude of applications and it came with the seals AND o-rings, i remember I couldn't get the seals to fit the first time but I thought I'd try again, i mean I'm a 210 pound guy and I used all the force I had pushing against that bowl, I honestly thought the tube was going to bend, if you find out I'd like to know but for now the o-rings are in.
They almost have to be. I've never had a problem with the cup type seals. I have a QFT 450 on Vixen and that's what's on her carburetor and I've changed them before. Easy peasy. So I bet that's what it is.