WHAT FITS WHAT ON EVO's
 

While I have a great book on this for 1936-1983 H-D's, there is not one for Evo's and up. Just picked up a '96 Softail Springer Bad Boy and would like to see a thread with whatever anyone knows (for sure) cross fits. My question is about wheels. Will a Softail FLSTF 16" solid cast aluminum FRONT wheel (part#4103-00) fit a springer front end? Can I use the 21" wheel's disc and spacers as well or will these need to be changed out assuming it fits at all?

While it can be made to fit it isn't a direct bolt in.
That '16 wheel has bigger bearings (also they are sealed) than your EVO.

About the only thing I know of that directly bolts on from TC to EVO is exhaust.

Not sure on the cutoff year but I think 96 or 95 and earlier are 3/4”. Newer goes to 1”

IIRC the cutoff year you are looking for is 2006.
After '06 they went to either a 1" or 25mm axle.
However in 2000 they went from tapered wheel bearings to sealed wheel bearings (which are crap IMO).

Axle size
 

I believe 1990-1999 the axle is 3/4", 2000 and up they are 7/8"

Definitely mine is 3/4".

It isn't practical to start listing all swappable stuff - that would be a lifetime's work. Best to ask specific questions, as you have for your front wheel. The short answer is that a later wheel can probably be made to fit, but you need to take into account a variety of things.

The early sealed bearing wheels can take 3/4", 1" and 25mm ID bearings, as they all have the same OD. I've adapted a Deuce wheel from 3/4" to 1" and a later 25mm front SG wheel to 1". However the bearing OD is greater than previous tapered bearings, as also is the central mounting hole for rotors and pulleys. So your 21" rotor will not swap over, although you could machine the central hole larger, so it does fit. If you use a later rotor, with the correct central hole, check the OD of the rotor, to ensure it is the same OD as your current one.

As for spacers, they can be modified easily enough, or fresh ones made.

Many early sealed bearing wheels that had 3/4 axles require machine work to go to a 1" or 25mm axle...even though the the bearings will fit, the spacer between the bearings will not.

Putting a 16" wheel on an FX springer that had a 21" wheel is no problem IF you don't plan on running a fender...if you want to run a fender...break out the welder and make one..no one makes one for that application...and "making" a factory one work is harder than it looks.