Holley LS1 Fuel Rail Kit 534-220 | This fuel rail kit is specifically designed to work with the Holley GM 2x4 dual plane manifold. Working to utilize the technology of the LS pushrod engine and now mated with the impressive multi-carb looks and performance of the muscle car era in the tradition of the great dual Holley 4160 induction systems that competed on drag strips, in Trans-Am at Lemans in the 1960's.!