Gearcovers for alternator style Big Twins. In spite of the simple, elegant design, these gearcovers are tough as nails. Machined from a solid aluminum billet, they are extremely strong and are dimensionally more precise than is possible with a cast part. The finish is flawless, show quality polished aluminum. Available For 1973-1992 and 1993-1999 Style Engines. The latter should only be used with engines that have the crankcase breather routed through the cylinder heads.