Spent the weekend working on a sick baby, sick wife and incredibly sick self... so there was no progress with the project.
However, today I did order up a pair of Toyo Proxes TQs in their 345/40R17 size for an outstanding price (with free shipping) from TiresDirect.ne t. TireRack was useless as usual.
The Mustangs below are on a 10.5" (the black one may be an 11") wide rim and the Vette is on 11" wide rims out back.
I'll be trying these on an 11" wide rim, and have already fit a 315 under a stock frame G-body so this should be very possible with the notch and mini-tub.