I am a big fan of Thunder Tiger engines, bkayani, and would never talk anyone out of buying one of their terrific engines. I am confident that you'd be very happy with a TT Pro .61 engine.

If you want to learn more about JBA, please check out Ed Moorman's (an engine columnist for RC Reports) thread about the JBA .56:

http://www.rcuniverse.com/forum/m_67...tm.htm#6762745

I actually bought a JBA .56 and had it shipped to Ed Moorman. He tested it and benchmarked it side by side with his O.S. Max .55 AX, which is one of Ed Moorman's favorite engines. Ed was impressed enough with the test results that he ordered his own JBA .56 shortly after mine arrived.