I have a twister that was built by Clarence Lee. I think he hand fits the engine. I am not sure if there are any porting modifications. I recorded the following with 15% Powermaster blend:

APC 11x7 with stock muffler with baffle 12,000 rpm
APC 11x7 with stock muffler w/o baffle12,700 rpm
APC 11x6 with mac 10cc pipe14,300 rpm
APC 10x8 with mac 10cc pipe14,700rpm

I do not have a Jett Stream muffler that fitx this engine. I have flown this engine on a World Intruder, but had to had weight to the front of the plane to balance. This might be a good option if you are needing a light engine. For reference, I am runnig a Rossi 60 long stroke on the Intruder with a JettStram 60-90 that turns an APC 11x7 at 14,300 rpm with spirited performance. Another light engine option is the Evo 60 with the blue Jett Stream. I have one that was on a Phoenix 7 turning APC 11x6 and APC 10x8 both at approximately 15,200 on 15 % Power Master. Good luck with our choice.