M8 Softail Big Bore Kits

S&S Cycle - 128" Power Packages fits '17-'20 M8 Oil-Cooled Engines This Power Package increases your 114"/117" with a 4-1/2" stroke M8 to 128". It is available in a wrinkle black or black granite finish and your choice of cylinders with or without...

S&S Cycle - 124" Power Packages fits '17-'20 M8 Oil-Cooled Engines This bolt-on Power Package increases your 107" M8 Engine to 124". It comes in a wrinkle black finish and is available with or without fin highlighting. You can also choose between a...

S&S Cycle - 136" Big Bore Cylinder Kit fits '17 & Up M8 Engines S&S Cycle's Big Bore Cylinder & Piston Kit delivers a mighty bore increase (4.320") that, in turn, delivers a huge power increase! It is compatible with stock crankcases,...

S&S Cycle - Wrinkle Black 124" Big Bore Kit W/O Highlighted Cylinder Fins fits '17-'21 107" M8 Engines This is a bolt-on kit that features the biggest bore possible with no machining of the crankcases necessary! It includes all of the required...

S&S Big Bore Kit for M8 Harley Softail & Touring '17-Up This S&S Big Bore Kit is for Milwaukee-Eight Harley Softail and Touring models 2017 and up, including Softail Heritage Classic and Breakout. Available as a whole kit or as a cylinder...

S&S Cycle - 128" Power Packages fits '17-'20 M8 Water/Oil-Cooled Engines This Power Package increases your 114"/117" with a 4-1/2" stroke M8 to 128". It is available in a wrinkle black or black granite finish and your choice of cylinders with or...

S&S Cycle - Black 4.375" Stroke 129" Big Bore Cylinder & Piston Kit fits '17 & Up M8 Engines S&S Cycle's Big Bore Cylinder & Piston Kit delivers a mighty bore increase (4.320") that, in turn, delivers a huge power increase! It is...

S&S Cycle - Black 4.5" Stroke 132" Big Bore Cylinder & Piston Kit fits '17 & Up M8 Engines S&S Cycle's Big Bore Cylinder & Piston Kit delivers a mighty bore increase (4.320") that, in turn, delivers a huge power increase! It is...

S&S Cycle - Black Granite 128" Big Bore Kit W/ Highlighted Cylinder Fins fits '17-'20 114" 117" M8 Engines This is a bolt-on kit that features the biggest cylinder bore possible with no machining of the crankcases necessary! It includes all of the...

S&S Cycle - Black/Highlighted 4.375" Stroke 129" Big Bore Cylinder & Piston Kit fits '17 & Up M8 Engines  S&S Cycle's Big Bore Cylinder & Piston Kit delivers a mighty bore increase (4.320") that, in turn, delivers a huge power...

S&S Cycle - Black/Highlighted 4.5" Stroke 132" Big Bore Cylinder & Piston Kit fits '17 & Up M8 Engines  S&S Cycle's Big Bore Cylinder & Piston Kit delivers a mighty bore increase (4.320") that, in turn, delivers a huge power...

S&S Cycle - Wrinke Black 128" Big Bore Kit W/ Highlighted Cylinder Fins fits '17-'20 114" 117" M8 Engines This is a bolt-on kit that features the biggest cylinder bore possible with no machining of the crankcases necessary! It includes all of the...

S&S Cycle - Wrinke Black 128" Big Bore Kit W/O Highlighted Cylinder Fins fits '17-'20 114" 117" M8 Engines This is a bolt-on kit that features the biggest cylinder bore possible with no machining of the crankcases necessary! It includes all of the...

S&S Cycle - Wrinkle Black 124" Big Bore Kit W/ Highlighted Cylinder Fins fits '17-'21 107" M8 Engines This is a bolt-on kit that features the biggest bore possible with no machining of the crankcases necessary! It includes all of the required...