Hey, I just saw your message and I might be able to help. The 84 and 85 suspensions are the narrowest of the C4 Corvette suspensions. As I recall the front suspension is right at 59" wide. I have not narrowed a front end, but it would be simple to do. You will need a custom steering rack though to keep the geometry correct. Those can be quite expensive. The 2004 front suspensions are very wide and much more money. The 84 to 96 Corvette front suspensions are very good and quite inexpensive.
I have narrowed the C4 rear suspensions with good results. You can only take about an inch off each side without doing major surgery. The rear suspension geometry isn't that great, but it sure isn't that bad.
I see you have instaled some vette suspensions.Im looking at putting one on a old vw bug type chassie (70's)with a porsche 356 glass replica body.have you ever narowed one of these suspensions?and how did it work out? curently the bug rotor to rotor is about 55"(wheel mounting face). Im looking at a 2004 ish front end setup.I know the 84 stuff wasent all that great.I havent decided on rear setup yet, the motor is back there,it may have to have the early(84 type) with the forward links.Im not sure if there would be room for the upper A arms. I havent pulled the car apart yet, just trying to get some ideas&make some dissisions.& dont have the$ to go out and buy a A arm setup made for it.thanks for any info.