I did a little searching on Pelican Parts and found that Bill Verberg is running this set-up on his Carrera bodied car:
Rear: "9.5" +19mm o/s wheels w/ 275/40x17(11" x 25.7") tires are the widest that I could fit on my car."
Front:"8" +23.3mm o/s to +31mm o/s are the most common fronts. 235/45x17(9.4" x25.4") are the widest tires that I could fit."
He has a ton of info on this site:
http://members.rennlist.com/1976c38/index.html