I'm running SD headers on my car. Had them for 6 months, about 2500 miles. LOVE EM!! No silicone used, but get good band clamps for both the cross over and DP (or if you have your DP welded with the race pipe or cat no need for the 3" clamps). I have one leak, where the flange is at my DP but that's cause I used the cheap gasket that came with the kit. I'd use all your stock gaskets.