WHY?

No, heads never milled.Ive ran the stock intake up till now. I didnt use gaskets, just the valley tray with sealant, like i always have. I didnt even use sealant on the stock intake when i built the engine,..when i took the stock intake off, all there was is the valley tray and it never leaked..

Well there you go. Aluminum intakes MUST use a paper or composite gasket. I like the felpro blue ones.