JIMS case boring tool takes all the guesswork out of boring Twin Cam motor cases Designed to be used in a heavy-duty 15 in drill press Simply bolt case into the angle swivel base that is mounted to drill press, then install the case boring fixture (utilizing cylinder stud holes), set the RPM and depth of bore and start boring Bore cases from a 4 in bore to a 4-1/8 in bore and build (depending on stroke and bore size) a 100 in to 124 in new Dyna Twin Cam big bore motor This product can be used with Model Part # Harley-Davidson Dyna 06-Up CBTHD-1 Harley-Davidson Big Twin 07-Up CBTHD-1 Harley-Davidson Twin Cam A Cases (Except 2006 Dyna) 99-06 CBTHD-2 Harley-Davidson Twin Cam B Cases (Except 2006 Dyna) 99-06 CBTHD-2