I've flown both on DLE 55's
With the Mustang I'd say keep it as light as you can because you don't have as much power as the bigger displacement 55 and 61 engines. From my experience this Mustang likes power and speed and it will snap at low speeds with aggressive commands so keep its energy high when flying.
The Corsair will take both the weight and more power and fly great. I'm currently flying one with a Saito FG 84 which is a very heavy engine. You may find you need as much as 4 pounds of lead up front. That's what it took when I had the DLE 55RA in there.
Ive run gas boats on white gas as suggested earlier, camping fuel. Works great, the boats ran with 26cc Zenoha engines just fine, no smell except the oil. Maybe an option for you but you have the engines in hand sounds like so go with what you got.
Last edited by Chris Nicastro; 12-12-2016 at 03:53 PM.