Performance mods vs the stopwatch

Sag, chassis, suspension feel makes me go faster. If the bike gets nervous, I go slower. If I can't turn, I go slow. More power would do zero good for me.

After tyres, and as I'm a vet rider, the correct (read; lower) spring rates.

490 big bore kit...

Motocross is 90% rider, the biggest gains are with the rider, this is a good place to start...

Its awsome to see realistic answers here. I honestly expected to see fcp motor mounts or some other useless shit .  

I was racing on a shoestring budget in the early 90s, I’d ziptie broken plastic back together as many times as possible. But I always had good tires, clutches and suspension. When I’d pull up to the start, I’d look for worn tires on the line, hoping to find a couple of roached tires to line up between. It was amazing how often I’d find my two trash tires, pull up to the line and find myself between two bikes with perfect graphics and billet parts..