My coupe is lowered with Carl Nelson's lowering springs. I'm thinking of putting Alpina wheels (16 x 7 Front and 16 x 8 Rear) on my 2800CS. Would the fenders need to be rolled, or any other modifications made to fit the wheels?
The problem with 30 year old hand-assembled cars is, there are few absolutes. The anecdotal evidence on Alpina wheels combined with Carl springs is, you may have to roll the front fender lips. Or not... Seriously, it varies car to car.
Not only do the cars vary, like Tony says, but different brands and models of tires vary in physical size for a given size tire. For instance, the Yokohama AVS tires I chose to replace the Pirelli P700s in my last tire change have a narrower tread and where the edge of the tread meets the tires sidewall is more rounded on the Yoko than on the Pirellis.
I've also seen different Michelins in the same tire size, i.e. 225/50-16, which had different shapes.
The Pirellis I previously had were 225/50V16 front and rear and it is definitely necessary to roll the front fenders for that size tire. Also, with the 225/50s in front, the tire sidewall ticks out beyond the fender lip a little. The Yokohama 205/55s look a lot better, at least if you do not have the chrome fender extensions. I also have Korman short springs and Bilstein Sport shocks and the car is lower than stock, but not real low.