Overview The L-40 Alternator from B&C Specialty Products is a high-performance, belt-driven alternator for Lycoming engines that make ideal power sources for aircraft requiring ample electrical output, modest weight, and exceptional reliability. Weighing just 6.1 lbs., it is produced from all NEW components (absolutely NO remanufactured content), and features sealed heavy-duty ball-bearings and built-in cooling fans to insure trouble-free service that gives you the best value for the long term. There are similar-looking units on the market, but the similarity begins and ends there. Dynamically-balanced alternator rotors to promote good bearing and bracket life. Uniquely modify each alternator for use with a more sophisticated, aircraft style, external voltage regulator with over-voltage protection (such as LR3C-14 or LS-1A), instead of leaving in place an internal regulator better suited for automobiles. And on the L-40, a third attachment point to insure solid, stable support (look closely?many of the ?look-alike? competing alternators only have two attachment points). Available for both 14 volt and 28 volt applications, the L-40 Alternator comes complete and ready to install, with either a Boss Mount kit or Case Mount kit. The Boss Mount kit for the L-40 mounts on the machined pad on the bottom of the engine opposite the starter and uses a U-shaped bracket and two 5/16" national coarse bolts. The Case Mount kit for the L-40 mounts to the case halves by using the two 1/4" case half bolts. NOTE: L-40, BC460-H, BC410-H, and BC462-H alternators require external regulators - use: P/N 07-06742 (LR3C) for 14V Primary, P/N 07-06786 (LS-1A) for 28V Primary, P/N 07-03461 (SB1B-14) for 14V Standby, and P/N 07-03462 (SB1B-28) for 28V Standby.