Have to go with the new 4 star .20.
A .30 4 stroke should replace a .20 size engine right? I know the new 4 star is being flown at Sig with an Enya .19 and the airframe looks big enough to handle a 4 stroke .30 . Iwill check with Bob.
Have to agree with the high nitro in the little .30, I had one in my hands for a while (Magnum .30) and it sucked on anything less than 30% nitro.