You can always try it and see if you have flooding problems. This puts about 2/3 of the tank higher than the spraybar on your carb, which means the likelihood of siphoning and rich running is much greater than usual when the tank is from 1/2 full to full. Did you lower the engine when you mounted it? I have an inverted .72 Saito in mine, and the tank centerline is about 1/4 inch lower than my spraybar, which is about perfect, and I didn't change anything. My H-9 is the older version, maybe they changed the newer one some.

If you have to change the tank floor, consider a smaller, or different brand tank first, to see if a different shape tank will help. I can fly my Cub for almost 30 minutes befor getting low on fuel, because the .72 will fly it at 1/4 to 1/3 throttle, and mine has the added weight of floats.