Don't waste time trying to figure out which parts you need to get the performance you want--Trick Flow® has already done the work for you! These GenX® Top-End Engine Kits for GM LS1 are designed and dyno tested to deliver the performance you want for less than purchasing the parts separately. Each kit includes a pair of Trick Flow® GenX® street/strip cylinder heads, a specially matched hydraulic roller cam, roller rocker arms, pushrods, head gaskets, head bolts, exhaust gaskets, and balancer bolt.