Hi Rocky,
I guess the first question I would have is why you would want to put 8" wide rims on the front of a 1000TC? Even the factory did not bother with that.
I see two problems. First there is a clearance problem with almost any such wide wheel, both with respect to tire diameter but also fouling the inner fender on full-lock. Second, perhaps more importantly, a wheel with that kind of offset will really upset the scrub radius of the steering and overload the outer wheel bearing.
A standard wheel is offset such that the center of the wheel is roughly midway between the location of the two bearings on the axle. This maintains an acceptable scrub radius taking into account Ackerman characteristics and also distributes the load between the two bearings. If you move the center of the wheel outboard, in relation to the center between the two bearing on the axle, you are altering the scrub radius and putting additional stresses on the outer wheel bearing. A discussion of scrub radius effects is probably too detailed to get into here, but the bearing load issue is easier to understand. There are many good publications on Ackerman and steering design.
Bigger wheels mean bigger tires. If these are "modern" tires then they are likely to have more grip and adhesion as well. After all we are all hot-rodders at heart. Of the two bearings, the outer one is the smaller of the two. Now we are going to load it up with a bigger wheel, hung outboard, and with a much stickier tire. OUCH !! Remember that the Fiat 600 was designed around bias-ply tires, mounted on a 4.5 inch wide wheel, not high performance radial tires on an 8" wheel.
Of course we want our cars to "look good and aggressive", and there is nothing wrong with that. But it should be done in a engineering sensitive way. If you are going to use wider wheels, try and maintain equal amount of offset to the inside and outside. There is a reason why the TCR had such large wheel openings!!
From a competition perspective anything more than a 7" wide wheel in the front is probably counter productive. Even then, you better have a lot of horsepower to move that wide tire down the road. The same goes for the rear. I have found that a good combination, even for a car with over 100 HP, is 7" in the rear and 6" in the front. This is a good compromise between adhesion and frontal footprint.
Hope this helps.
Regards,
Paul Vanderheijden
Scuderia Topolino