8-bolt crank; fits the LSX 454, LSX 454R, and LSX 376-B15 engines only. Twin Disc XT Race Kit Moderate to heavy pedal effort, quick shifts, aggressive engagement, OE to moderate gear rattle; Disc surfaces doubled for better wear, heat capacity and longer life, further extended by ACT's exclusive diaphragm design; Carefully engineered, precisely assembled, accurately balanced, uses select ceramic friction materials for high heat tolerance and maximum performance; Recommended for race use only; 100% clamp load tested and dynamically computer balanced for smooth high RPM reliability T2R-G06 race, twin disc kit offers twice the number of disc surfaces for better wear, heat capacity and long life compared to single disc kits. These kits use a proprietary Positive Lift Floater System design, which results in quiet operation with no floater rattle and no posts to wear. ACT twin disc kits undergo an exclusive four-stage, heat-treating process on all diaphragms. The ACT twin disc features the ability to adjust for disc wear and provides equal disengagement for discs. ACT's 6-pad rigid race discs are made with high quality, ceramic friction materials. The chrome-moly hub is heat-treated for strength and durability. The lightweight, rigid design allows for quicker shifts and trouble-free service. All ACT twin disc kits include a CNC-machined and dynamically balanced flywheel to ensure trouble-free installation and operation. ACT twin disc kits include a pressure plate, two discs, a floater, flywheel and alignment tool. Some kits may include a pilot bearing and release bearing.