Re the 120 Sprink my original model flew with great authority on the 120fz (lovely motor)

Just to add a little more to the debate "The Boys" new wing with its mods and improved cad bits is a whacking 6 ozs lighter [8D][8D]

That Makes his leccy sub 9 1\2 lbs the Ic should easily match it. But you will struggle with CG with anything smaller than the 120 crank IMHO