Well, NOW you tell me! LOL.I never heard of HEMI intake "O" rings. I was almost at work today, still dark, and the boss called. Asked where I was, I replied, "I'm almost to the office". His response, "go back home, we are having a snow day". So, I spent the day finishing the carbs, fuel line, distributor install etc. I fired it up just now. No leaks so far....I will put my money on Superformance. So far anyway. I am sure that I won't have any more problems, if I do, I will post for help as always. Just wish I could take it out and test it, but I am 58 and wise, vs. 18, when I used to LOVE taking my 4 speed 67' GTX for drives in the snow!