I just weighed a Johnson 36BB and my Aero 35. The Johnson weighs 10 ounces and the Aero weighs 12. The Aero was designed for cowled in C/L precision aerobatic airplanes. The two ounce difference would mean very little weight needed in the tail to balance the plane. The Fox stunt would probably weigh less than my Johnson but too hard to dig one out.

As the areo was designed for C/L stunt, it didn't have to be a rocket engine. Look at the standard of the day. That was the Fox 35 stunt. Very low on power compared to the average 35 engine like Super Tiger, Johnson, K&B or the Fox 35 and 36X's.

As far as being longer, so? You just moved the firewall back 3/4 of an inch like I did on the Ares. At least you didn't have that big cylinder sticking out of the airplane and have to cowl that big cylinder in.

Finally, it was DIFFERENT! Fun to show up at a contest and have everyone looking at your airplane.