Mark, I don't remember what size tank came with the Waco, but I have a DLE20 in a Top Flite Mustang. I am using an 8 oz tank and fly for 10 minutes at 1/2 to full throttle. I never have ran out. Always have couple ozs left. I have the DLE 30 in my Waco and just had to cut the cowl on the bottom. I used a jtech wrap around muffler.