To pump, or not to pump
The need for a pump will depend on your tank location and the type of flying you do. If you mount the tank right behind the firewall, and on centerline with the carburetor spray-bar, you should be good without a pump. If you move the tank (clunk) back more than 10 inches away from the carburetor, you will probably need a pump. Also, if you do aggressive aerobatics with tight loops, acceleration on up lines and such, you probably will need a pump also.