Purchase the K&N filter (K&N part number HD-0800
I did this, bought all the "Roll your own" items listed which was a nice cheap way to go!

Couple of silly questions though:
1) My K&N doesn't look like the one in the pic below (
with thanks to Steve G for the post of the original pic) at all! Instead of having parallel sides, it's more conical in shape i.e. the outside diameter is smaller than the inside, but it seems it fit the backplate fine - am I using the correct filter?
2) It came with a self-adhesive rubber ring, which I stuck on the outside circumference of the filter, thinking that would be the best thing to do, avoiding metal on metal (i.e. the ham can against the filter) contact. Correct?
3) The bolt that fixes the cover to the filter - the big one in the centre - was VERY tight to go in - I double checked that I had it on the right thread twice, and the threads
looked like about the same pitch, but again this had me wondering if I'm using the right filter element! Is it usually very tight like this?

? I had visions of it winding a nice spiral of metal into the inside, but I wasn't going to take it off again to check!

4) Silliest question of all - nowhere, not even in the supplementary workshop manual, does it say which way round the cover (FLHTCUSE) goes. And it never occurred to me that it wasn't symmetrical! I assume the shallow end goes to the back/deep end goes to the front, but can someone just confirm that?
Sorry for the silly questions guys!

Jim