On 10/26/2018, Mark Wellard in Australia wrote:
"I have been fighting with the Kopex air tubing in front of the radiator support panel on my twin cam. These are not particularly easy to install because of the angle and cramped space available. The main problem is that the diameter of the ducting [ID] is the same as the tube [OD] in the radiator panel, and when an angle is required, the lack of extra diameter becomes a real problem.

I managed to mangle the duct tubing a few times before succeeding with the aid of the attached tool to expand the diameter of the Kopex tubing. It was borrowed from a friend, Dan Casey, and enabled expansion of the tube by about 1/8-inch�. With this expansion it is possible to get the tubing about 1-inch �onto the radiator duct, which is sufficient to make it stay in place (although not entirely covering the metal tube)".

What I first thought might be a clutch release arm pivot bolt turned out to be a rocker cover nut and a welded threaded stud.