Steph, my point was that a LS400 is not a Porsche (or Lotus) although you would be surprised at the performance, and a FLHT is not a sport bike. Trying to make one into the other will rarely end in a positive outcome.

Now, I've ridden fairly hard through the mountains, and setting the air ride PSI to 35-ish (my bike has a sticker that says something like 10-40PSI) gives a pretty firm front end under breaking. I think the later years say up to 20-something, but as far as I know, all the parts are the same. Are you sure the air valve is working properly? It can click and all but still not be sealing. Put a good amount of pressure in it, push up and down on the handlbars with the wheel up against a curb or something. Pull the brake lever on (ignition on because the valve is in the tail light circuit) and push up and down again. You should be able to feel a significant difference if it is all working properly.

Otherwise, different springs and/or oil seems to be a popular mod.