25mm is max spacer width that will fit under rear quarter with stock wheels. (new mounting options required) Using existing wheel studs, experiment with spacer size using fender washers until you meet minimum of 6.5 turns of hardware engagement. Chose hub and wheel centric spacers.
I am chasing the same problem on a GTV6. On front with installed wilwood dynapro brake calipers that have changed the “x-factor” from face of wheel flange to caliper face that requires a spacer for the stock Campagnolo wheels to fit. (15” Team Dynamics wheels fit without spacer)
1982 GTV6 wheel studs thread standoff is 33.5 mm from face of flange. To get the stock Campagnolo wheels to clear the caliper I need approx 10mm of spacing. This doesn’t leave enough bolt thread to complete 6.5 full turns of hardware engagement.
Add spacer (10mm), open Campagnolo lug seat hole to allow extended thread lug nut to back thread and grab; Downside safety.
Add longer 12 x 1.5 mm wheel spines studs and add spacer; use open bulge lug nuts or long body lug nut; not much downside other than longer wheel studs.
Grind down interior of magnesium Campagnolo wheel face buttress 8.5mm to add needed clearance. Hmmm.
H&R Trak Plus DRM 25mm spacers might be an option. Downside is the Team Dynamics wheels need to be cavity back to accept the old mounting stud.
Post what worked for you.
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