A leak down test would be good, I also think a compression check would tell you a lot. Even better if you could compare it to others!
What's the maximum RPM you're turning, and how does it compare to others, and what's the stall RPM on the clutch??
Where are you getting beat; through the corners, out of the corners, down the straight??
What fuel are you using? Is it controlled by the rules?
What are your weight percentages, front left cross?
What stagger in the rear?
What tire treatment are you using?
Just to show you that; "tuning is tough" (Al Nunley)
Small restrictor plate engines on a gear run is a whole different beast.. In most cases these gear rules have the engines winding out on rpms.. The correct setup that would run good on the track would be a turd on the dyno.. The kart that can turn the most rpm's usually the one to beat persay..
WE have taken these engines legally upwards to 6200-6400 rpms..
From what you listed you indeed off the entire set up..
Drop timing down around 32... Get that 158 head off the engine,, you need a smaller port head for red / green plate engines.. Drop the jetting down will help,, BUT you really need a carb built to that exact application... Ofcourse we build a carb (Holey Moses) for this application,, and even with that you have to experiment a tic to dial it all in..