I think the wide glide front end is the same as the Deuce/Softail Custom front end. I know that you can convert the front end of a Low Rider to a Wide Glide front end. And...I think on the pre 2003 Dynas, the frame was the same between the low rider, and the Wide Glide. The rake was actually in the triple trees. Don't hold me to that 100%, but I know I read that some where. So, if that is correct, all you need is a a Wide Glide front end(Triple trees, and forks, and risers) and bolt them on. I could be completely wrong though.
Harley makes so many minute changes nowadays it is hard to be sure. You are surely more likely to get a bolt-on mod if the front end is the same year as the bike you are swapping to. By front end are you getting everything ie forks, brake caliper and lines, wheel, fender, etc? The main things I think you would want to know is if the stem is the same length and the bearing the same diameter. Even if the bearing angle is different you can fix that by either putting on bearings to match the race or pounding out the races and putting proper ones in place.
I put an upside down fork from a CR-250 dirt bike onto a 20 year old XR350 once. It was no where near a direct swap, in fact probably about as far from it as you could get. But in the long run it really didn't take a mechanical engineer to work out the snags. If you already have the front end I say mock it up and see what doesn't seem right.
You might want to wait till winter to do it because you might run into machine work. I had to remove some taper on my stem to do my fork mod and that took about two weeks alone.