Thanks for the compliment on the car! It's been a labor of love (ie. wrench, beer, checkbook :laughing: ).
The TT II's are 17x8" with standard 4" offset all around. No clearance problems... as a matter of fact, I have more clearance since the sidewalls don't bulge out as much. The tires are Nitto 450 Extreme Performance (255/50). It's a perfect match to get the stock 27" diameter. You'll like the Nitto tires if you go that route. Excellent performance...
FWIW, the TT II's have had their share of problems. Mainly runout (wobbles a tad). I've replaced one already, and the local dealer is bringing in another new set to try and find some good ones to give me a good set. I've heard it's not all that uncommon with the TT II's. Maybe the 17's are tougher to get right than the 15"? Dunno. I tried to find other wheels to replace them, such as the Edelbrock 409, but they had some problems with their molds. And the Boyd Coddington Genesis 5 is cool, but they only build to order and I didn't want to take the chance or wait. So now just waiting for some new TT II's to arrive. I hope they work it out, 'cause it's a great looking wheel on a C3. :cheers: