I can't for the life of me get these intake seals to actually seal. At this point I've come to the conclusion the flanges are warped. Trust me I've tried everything. Grease, silicone, I've been installing them the correct way each time, quarter turn on each bolt in an even manner. I've ordered the oberon intake flanges with the dual o rings. To me this is a far better design. I will let everyone know how these end up turning out. I bought an additional set of o rings with them.. it was 126 usd shipped to me. Says 9 days shipping time. 126 bucks is worth it because I've dropped the motor 3 different times an each is the same. My time is worth the 126 dollars. The lost riding time is worth the . dollars. My sanity is worth the 126 dollars. I think you get my point. Like I say I'll let everyone know if these are worth your time and money