Joe, Contact Mike (Grimracer) give him the dimensions of the fuel cell area and he will build ya a custom tank to fit. Can give you the exact capacity as well. You won't regret getting one of his tanks. Top notch.
I already own two of his tanks for my tunnels. If I knew how many oz. I need For heat racing, I woud have no need to over fuel and be heavy. Thus using small screw in eye lets with small fuel tubing works great to hold the tank.