I really like the heaters that fit into one of the freeze plug* holes in the block. They seem to heat better than the external ones that plumb in with hoses. Much neater appearance as well. If you can't find one from Branson, you might be able to pick one up from a Cummins dealer if you give them the engine numbers.
*For those sticklers out there, yes I know they aren't actually freeze plugs, but ports in the casting that allow them to remove the forming sand that is used to form the coolant passages in the block. I've had that drummed into me several times over the years. The plugs won't protect the block from damage due to frozen coolant.
'56 IH 350 Utility Gas, '47 Farmall H Gas, '08 Bobcat Toolcat 5600 Turbo
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Stihl, Ariens, Tecumseh, LCT, Lauson, Kohler, Subaru and Lawn Boy Certified Technician with over 15 years experience.