In regards to suspension, get rid of all brake dive. If the track is smooth, I like a rigid feel. Loose suspension just gives off a wobbly feel.
Brakes, sipe your shoes, sand them to remove glaze, and sand the inner drum surface. Not alot, just enough to scuff up the shiny surface. You can make your lelue drums work perfect, despite what other people may say. (Mine will lock up the rear and stoppie the front if I want them to.)
Get compressionless cables and levers with the right pull.
Also, remove the red plastic plug and drill some little vent holes in the brake plate for some airflow.
Set up your handlebars for comfortable steering, not just for a low tuck straight line position. You want to be relaxed and comfy, not fighting your bike thru corners, and it helps with the death grip pain and numbness.
Get your bike as light as possible. Alloy rims help. Mags weigh a ton. Remove everything you don't need.
Gear for the track, not the street. If it's a short, twisty track, gear low for cornering speed. If it's got long straights where faster bikes always catch up or pull away, gear it higher to stay up front.
Same goes with pipes. Tight tracks, get the pipe to hit early as possible to stay in the powerband.