A rocker box, pushrod assembly, oil delivery system, tappets and tappet guides are provided for an engine, particularly a shovelhead motorcycle engine. The rocker box includes a separable upper portion and lower portion with a seal for sealing the upper portion and lower portion when coupled together. The pushrod assembly includes an adjusting unit that collapses into a pushrod shaft. The oil delivery system includes an oil passageway(s) in a rocker shaft of a rocker arm assembly, and at least one of an oil passageway(s) in a rocker box and an oil passageway(s) in a pushrod assembly.

An installation device and method for installing engine components, such as bearings and seals, on an engine. The device including a first connection member that couples to an engine and a second moveable member configured to translate relative to the first connection member. The device also includes a rack and pinion arrangement that provides translation of the second moveable member relative to the first connection member.

An installation device and method for installing engine components, such as bearings and seals, on an engine. The device including a first connection member that couples to an engine and a second moveable member configured to translate relative to the first connection member. The device also includes a rack and pinion arrangement that provides translation of the second moveable member relative to the first connection member.

A shift collar for a transmission is disclosed. The shift collar includes a gear engagement surface for engaging a transmission gear, at least seven engagement dogs projecting from the gear engagement surface, a shift sleeve engagement surface for engaging a shift sleeve, and a plurality of grooves formed in the shift sleeve engagement surface for engaging corresponding splines on the shift sleeve. Preferably the engagement dogs are arranged on the gear engagement surface such that each of the engagement dogs engage one of a corresponding number of engagement pockets in the transmission gear.

An engine crankcase and transmission assembly includes a transmission housing including a forward mounting portion and a crankcase including a rear-mounting portion configured for mounting to the transmission. The rear-mounting portion of the crankcase includes an upper section and a lower section spaced apart from the upper section so that the first transmission housing and the crankcase define a passage there between when mounted. An oil sump at a lower portion of the crankcase including an expanded section with an outer surface extending rearward beyond the rear mounting portion of the crankcase. An adapter provides for mounting to a second transmission housing. The crankcase receives interchangeable first and second oil routing devices with oil line fittings for receiving complementary oil lines. The first oil routing device includes first oil line fittings for receiving first oil lines extending toward oil fittings on the first transmission housing, and second oil routing device includes oil line fittings for receiving second oil lines extending toward oil fittings on the second transmission housing.