John,
I have the Aggressor 2 with a KBV .82 it works outstanding I have around 150 flights on mine. I have been told by those more knowleagable than I that I can't put the bigger fuel tanks in the plane. They won't fit and you need them for the .91. I recomend that you contact BVM they have always been very helpful with any and all questions. Although the look I get from BV when I show up at a jet fly is always precious when I bring out my Antique.
I think I have the info for the guy who did the KBV for BVM. He has worked on my engines at a very reasonable rate.
Sparky