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No problem with the 8 inch wheels. You'll still have a lot of room.
17 inch wheels on my 68 and 18 inch wheels on the 70. There's a big thread here on CF C3 about 18 inch wheels. With 18 inch wheels, you have a big selection of tires. With offset trailing arms, you can get 9.5 inch rim widths on 18 inch wheels.