Today, life is a bit easier! Trick Flow® GM LS engine steam line fittings are available to upgrade the factory steam tubes of your modified LS-powered cars and trucks to update your race car plumbing system. The fittings are black anodized billet aluminum and attach to the corners of your GM LS cylinder heads. They feature -4 AN male threads and include O-rings and stainless steel bolts. Upgrade to easy with Trick Flow® GM LS engine steam line fittings.