I've got the ultimate mod to make you faster. And it won't cost you anything but some gaskets.
First off, pull the exhaust, carbs, and cylinders. Then turn the cylinders backwards. Intakes facing forward, exhaust back.
Reassemble accordingly. The new design will force air into the intake side like a supercharger. You might have to modify the pipes to fit. If it works the way I'm hoping, you'll beat that bastard 300ex. Keep us posted