Why does my Franken driver work?

[2bGood]

I have wanted to cut down a driver for while so I bought a beat up Superquade (the same head I have now) on ebay to play around with. It had a x stiff Aldila NV55gram shaft on it. I play stiff, and my plan was to reshaft it, but I figured what the hell and cut this driver down to 43". I figured I would have to adjust the swing weight, but all the same I gave it a try.

WOW. This is very very straight and as long or maybe even longer then my Superquade with 45" stiff 65g shaft.

So what gives, why does this work, the shaft it too stiff for me, swing weight must be off, but yet it feels and flys great.