Fuel Tank Size

I'm helping a buddy put together a front engine dragster and are wondering what size of fuel tank we should put in the car? Mild blown alcohol 540" BBC,6-71,Bugcatcher,110 pump,15-20 psi boost,1/4 mile racing.

I'm thinking 5-7 gallons?

 

At least 5 gal 6 or 7 would be better.

 

My 1471 enderle bbc uses 2.5 gallons on a 6.60 pass being towed up and back. That's with the bv set leaner than some but rich enough to keep the temps down. If i was driving it I would definitely need 7 gallons, but my 4.5 gallon tank works fine as long as I'm careful.