Pretty close only counts in sword fighting.
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Contact your closest International Truck parts department. The part # you want is 86543R2 which they call a "seal." They may not have in stock but can get from their warehouse in a couple of days. These work great for all 47-55 KF, HJ, and Darrin.
Stick the bottom bellows section through the mat/floor board and into the engine compartment. It won't move and will ensure a great seal at the floorboard. As a KF vendor in a former life, I used to sell these to club members and everyone seemed very happy with them.
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Mike