Yeah, I don't know, I ordered the 1984 just because it's a higher #, lol. Last weekend we changed the cap, rotor, and found the coil was bad too. I posted it on another thread but, my son noticed some discoloration on the coil, took a spray bottle of water and sprayed that area on the coil while idling. Each time he did the engine stumbled and almost died. Then he sprayed the other side of the coil - no problem. After changing it my engine ran good.