Gary,
Your engine will inhail the same volume of air whether you are there or here are 24' above sea level. I've run at tracks that the air was measured at 3,800 ' and it runs a little rich because of less oxygen, just go down 2 jet sizes, ran 2 tenths slower.A simple carb change may save you an expensive tear down.
Your engine should tolerate more timing, I'd up it to 36* total.
You have a dual plane intake so you can run a bigger carb than if you had an open plenum manifold. If you put on a 800 double pump carb any 1 cylinder would only 'see' the righ or left side of the carb at any one instant, it would 'see' 400 cfm of carb. EG: I run dual 600 carbs on a blue thunder dual plane dual quad intake. It never bogs and has crisp throttle response because any 1 cylinder only 'sees' the left or right bank of carbs at any one time.....300 from the front carb and 300 cfm from the back carb= 600 cfm.
Good Luck,
Perry.
