Re: 64/65 tire size changes (vetzs)
The '65 OE 7.75-15s were bias ply, not radial. The first OE radials on a Corvette were GR70-15s in 1973.
The best performing radial for your '65 would probably be the Pirelli P4000 Super Touring, 215/70ZR-15. The speed rating in the load index is "W", 168 MPH, and they are only available in blackwall. Michelin also makes a V-rated (149 MPH) Energy MXV4 in this size. Both of these tires are "all-season touring tires" which are aimed at high performance sedans and provide good midrange handling with good ride quality. There aren't anymore summer high performance tires in this size, or any size that provides close to the OE revs per mile figure. The OE 5.5" steel wheels are at the narrow limit for a 215/70, but are acceptable and the tires should not interfere with the fenderwheels. They will fit on a '67 with 6" Rally wheels, which have less positive offset.
I think the best setup would be to buy outright a set of repro '67 6" Rally wheels (be sure the offset is the OEM +0.06"). The offset on the 5.5" steel wheels is +0.44", so your track will widen 0.76" and the 215/70 won't look so pinched in at the bead.
As far as I know the OE '65 wheel covers will fit on the '67 6" Rally wheels.
P.S. I forgot. Probably the ultimate performance 215/70 is the "vintage" Michelin XWX 215/70VR-15 available exclusively from Coker tire - about a kilobuck per set.
[Modified by SWCDuke, 4:18 PM 6/13/2002]