My wonderful mother-in-law just bought me an evolution .61 for easter thanks to my wife for giving her the idea. Anyways I have been wanting a new engine for my Sig Kadet lt 40. I originaly wanted a .51 because i thought a .61 would be too big. anyways my question is, Is my new engine too big for my Kadet Lt 40? And if not Are there any modifications I need to make to the Kadet? Any help would be appreciated.