Heh, I played with my 450's also yesterday...man they are lightweights after being used to the bigger stuff for some time, lol. Not so sure that 5mm shaft will hold the mass of a 425+mm head. I guess if you chance it, DS95's have to power to drive it though for sure. Although maybe doubled-up frames, figuring out how to get a thicker main in there, etc. might work, hmmm. And probably a bigger motor... There is that Align 500 size Cobra
I think I took off around around 1" off of mine, pretty much just matched up where I wanted the head and tail to be on the fuselage and went from there. I wasnt trying to duplicate a T550 length doing this, although that fuselage had a T550 in it before. I'm not sure I wrote down the exact length, I'll look around if I did note it somewhere and if I find it I'll post it.
Those blue heatsink HW esc's are nice, and have an excellent upgrade path should you want to have a Vbar doing the governer duties for dead-solid speed regulation...work great with the Vbars