3/8" (right side) and 1/4" thread (left side)

1/4"-20 threaded bolts

Switch head dimensions: 12mm dia

XL (REAR AXLE)

the model year difference is found in the mounting hole type (65-84 countersunk & 86-06 non-countersunk for allenhead type bolts) only

JAMES EXHAUST GASKET & MOUNT KIT Sportster 4&5 speed 3/8" (right side) and 1/4"Includes 84 90 10 up style pressed wire gaskets, 4 chrome washers and 4 chrome plated acorn nuts. Note: This 84 90 10 up style is preferred by many for better flow characteristics. Note: The 91 09 late style is a conical (tapered) shaped gasket that was introduced by The Factory in 1991 and replaced, again, with the better early style in 2010. Note that the early style will fit all models and is generally seen as the better gasket design. Fits: > 84