That's understandable.
I've seen some 18" rims by ROH, the Azzurro, but the design of the one I saw, IMO, wouldn't look good on your car.
ROH sells those rims with tires for over $1700 per set of 4. I really haven't seen any besides those. I would think the fattest tires you could get on that car would be 315s.
Honesly man, getting some 17x9 or 18x9 would look pretty noce on your car.
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351W-powered 1979 Ford Mustang notchback
Stock 5.8L under custom made 4" cowl, C4 w/ shift kit
Holley 750 cfm, Edelbrock Performer RPM intake
1 5/8" MAC shorty headers, Al driveshaft
2.5" Off road H-pipe, 2-chamber Flowmasters
Front: 225/60/15, Rear: 255/60/15 Eagle GT II
Weld wheels (15x6;15x8), 8.8" Rear w/ 3.55s
14 x 4” K&N air filter.
Only a couple of weeks b4 Project FOX begins!!! 
"Red, thou art my companion. Hasten now your quickened metamorphosis to Green that I may conquer all who dare abide there beside me. May they be left thither behind burnt black." ---Fox Body
[This message has been edited by Fox Body (edited 09-25-2001).]