Wheel swap
 

Can I swap a 2003 Road King wheels for a 1986 Electra Glide?

Can you...yes
Will it mount up with out any other extra work....no

Your 86 has 3/4" wheel bearings the 03 has 1". There's adapters available but you will need to play with the spacers to get the correct alignment and width.

Not the same type wheel but this will help you with the process of fitting the wheel.

https://www.hdforums.com/forum/evo-c...-3-4-axle.html

Wheel swap
 

Sorry for the late response. Thank you for the information.

There are several challenges to be overcome in making a swap like that. As TwiZted points out the bearings are different, but so also are the ID of rotors and rear pulley, also your rear brake rotor and caliper are not compatible with later rear wheels. So it can be done (I have got later wheels and brakes front and rear), but it does require some effort and extra parts.