WizRacer, I put a set of my foam core 20 size (27") floats on my SE and had a ball with it. The plane didn't even know it had floats on it! The only problem was the floatation was barely enough. I made a set a little larger, but haven't flown it yet. My 20 size floats sheeted with balsa and with the nylon mounting blocks weigh in at 4 oz. each. I think the 40 size (34") would be OK but a bit too large....Seaplane