5/16-18 to 5/16-24 X 1-11/16. Mount exhaust to cylinder heads. Note: Exhaust studs as used in the M8 engine (OEM 10900015) is of a slightly different design, with a small protruding hex-shaped outer-end to aid initial stud-installation, but early style studs will still fit.
Fits: > 84-20 B.T.; 86-20 XL; 08-12(NU)XR1200; 87-10(NU)Buell XB
Koyo=former Torrington. When still present it is advised to replace the low cost OEM needle bearing in 92-99 Evolution Big Twin models marked 'INA SCE 138 USA' with a 'full needle' bearing to increase reliability. Especially important when using higher lift cams, which increases stress in the camshaft bearing.
Fits: > 58-99 B.T. (excl. Twin Cam) (NU)
Replaces OEM 8990/A style ball bearing. This bearing will fit will fit all models as front & rear outer cam bearings. Note: The MoCo has redesigned the Twin Cam rear outer cam bearing from ball to a roller bearing style in 2001. This was done to help prevent failing ball bearings on, specifically, rear (=driveside) cams that are heavier loaded. This 01-up roller style bearing is a 3-piece design that is more heavy duty than the roller bearing. No other parts changed during the bearing changes. The early 99-00 style ball bearings will still fit all 99-06 models front & rear. Using front & rear ball bearings present no issues on cam driven gears.
Fits: > 99-06 Twin Cam (excl. 2006 Dyna) (NU)
S&S, needle bearing camshaft. 'Full needle'
When still present it is advised to replace the low cost OEM needle bearing in 92-99 Evolution Big Twin models marked 'INA SCE 138 USA' with a 'full needle' bearing to increase reliability. Especially important when using higher lift cams, which increases stress in the camshaft bearing.
Fits: > 58-99 B.T. (excl. Twin Cam) (NU)