For 2004-Up there are front and rear pulleys available, beyond the factory offering:
32 tooth Front and 66 tooth rear for Interstate riding. Reduces rpm's 10.3% and 12.6% combined. The following rpm's are rounded for easier comparison.
Interstate Riding
1200 with factory 29/68
70 mph = 3252 rpm
75 mph = 3480 rpm
with 32/68 pulleys
70 mph = 2950 rpm
75 mph = 3150 rpm
with 32/66 pulleys
70 mph = 2850 rpm
75 mph = 3050 rpm

883 with factory 29/68 These are 2010 and up. The 2004-2009 had 28 tooth front, another ~120 rpm at 70 mph.
70 mph = 3640 rpm
75 mph = 3900 rpm
with 32/68 pulleys
70 mph = 3300 rpm
75 mph = 3530 rpm
with 32/66 pulleys
70 mph = 3200 rpm
75 mph = 3430 rpm

City riding a 28/70 combination is available; about a 6% increase in rpm's.
Quicker around town, more rpm on the Interstate.