WHY?

Things just keep going down hill with this dart. I installed the new street dominator intake on my 440. Did it like ive always done, new valley pan and GOOD sealer, and it wont idle because its leaking along both sides so bad! I mocked the thing up and the bolts went right in and all, but its leaking..I can spray carb cleaner along the sides of it and it will rev a little. Ive sure know my share of people that have put aftermarket intakes on with no issues, so i dont understand this..