63798-99A is a 5 micron chrome
63805-80A is for my 2006 sport R 1200...
My old EVO dyna glide used the long filter, HD said It wasn't enough filtering capability for the 10 microns needed on the 2000 TC,,,, I used it anyways (no problems)
I also was told that the 5 micron (63798-99A) replaces all twin-cam oil filters.... So good luck if you want a ten (10) micron.... All you will get now is the 5...
I asked HD parts guy, when buying the filters, WHY they don't publish the micron number on the oil filter boxes anymore...?
They just don't was the answer........ JUST answered as LAZY as it sounds......
I use the big long filter on the dyna that was used on the EVO....
This time I bought a Proper Little oil filter for the sport..
I know you CAN"T use a TC on a sport,,,Engine damage Will result.....
Completely different style of filter needed..
signed....BUBBIE