Description 600 Watt, 120 volt Engine Block Heater. 1-5/8" diamter, freeze plug mount. Fits DSD & ESD659 (362 CID 6 cyl), 660 (363 CID 6 cyl), 680 (380 CID 6 cyl). Install 2nd and 3rd left side. Point element up or down. Two heaters recommended. This item is a suitable alternative for the following: 106725A1, 310-0061, 3100061, 407046R92, 407046R93, 878057, 998849C91, A-407046R1, A407046R1