Im not a wheel expert, but here's some comparisons I was able to calculate.
The wheels will probably fit but they will look anemic.
Green is the refresh wheel, Orange is the original forged arachnid for the older cars.
Rear:
Front
Both front and rear wheel will be in the fender ~12mm.
I would suggest more importantly, you will have possible traction issues. With the stock tires, the car can easily skate at 50-80mph in nice dry socal asphalt.
I had a set of the Grey Arachnids on my 85D way back in the day, but I sold them on a deal I could not pass up. Loved them, so I feel your urge to keep them.
Personally I took delivery with the 19" wheels and promptly swapped them out for a lighter forged aftermarket wheel. I even went so far as to get them square, so I can do tire rotations. Nothing rubs, no issues over 7000 miles. Car ran 9.20's in Las Vegas drag strip, so no performance hit.
Mine are 20x10 TSW's 35mm offset, 275/35/20 MPS4 tires.