Petrol tank

I have been looking at petrol tank for my track car, no one offers a solution to what i want. I want the tank to mount under the the floor in a standard position as it is the best place. Now i am going to make a split mould of my standard tank, it will be modified some what but the basic shape will be there

I will probably make it in a kevlar and carbon/kevlar layup and also make a carbon underbody protection etc etc.

My main issue was once i have made the moulds i was going to split the tank to see the insides and add some baffles and hopefuly aid in the tank in fuel surge, does anyone have any suggestions in what to add, i will get pictures tommorow of the tank

Cheers