I had an OS 1.60 twin in a GP Super Stearman and it flew very well and sounded awesome. It was very similar in power to my friends PT-17 with an OS 1.20. One problem I had with that plane and engine combo was flooding, there was no way to change the height of the fuel tank or engine. I also had the 1.60 twin on a 1/4 scale GP Spacewalker, another great combo, no issues at all with this combination.