Bought this a while back for my Hirobo Super Cobra which ran a 61 in it. It was mounted to the mech's (S-60II) to verify it would fit and work with the scale in-fuselage muffler. The only mod done was clip one end of the throttle arm as seen in the pictures.
I was happy with the power that the 61RX-H put out so I never needed to make the swap. Stan AKA Doorman now owns the Super Cobra & I have no use for the 91.
Price is shipped in the lower 48 for $150.00 I will ship world wide for actual added postage.
Sorry but not looking for any trades.
Thanks for looking and have an awesome day
Best regards, Scott