Thanks gearhead.
I see now there is no need for me to get a new flywheel, just drill out the crank holes (and resurface and balance of course)
And I asked this on another thread...both 10.5 and 11 inch pressure plates use the same mounting holes, right? So, I could use either size with a particular flywheel-just match the clutch spines (26) to the T5.
It's starting to be clear now; thank you all for the advice.