FYI - the engine is a '59 235. The old belt size was a 15385 and the new belt is a 17385. The guy behind the counter at my FLAPS tried to convince me that the first two digits on the belt number are the width of the belt in millimeters, and the last 3 digits are the diameter in millimeters. However, this can't be right, because the new belt measures exactly 1/2-inch wide. A 17-mm belt would be 0.67 inches wide (there are 25.4 millimeters in an inch).
Anybody know how fan belts are measured?
