Find a NOS or rebuilt Delco Remy, the gear reduction ones usually give better service after being rebuilt. Or buy two imports for the same price and have a spare. The ones from Taiwan are generally better than the mainland ones. The imported ones are usually new and no core is required. 27mt is the original, 28mt is the gear reduction, if i remember correctly. Both are available in 12v and 24v, so make sure you order the one you want.