I first looked at replacing the studs so I could use 10mm thru-hole spacers on the front and 20mm on the rear. Below is the M14-2.0 Dorman 610-485 studs which comes in a 10-pack. I would need to machine them to a shorter length which is no problem. The problem is all the work to install them. I would need to remove the half shafts on the rear and pull off the knuckle on all 4 corners. Then I need to buy 1 time use bolts. I might as well buy new wheels.
So, I bought a set of Adaptec Spacers (LINK) which are US made and appear to be of descent quality. The thinnest I can get for the front is 15mm. I went with 20mm on the rear.
The studs are cut with the thread lead-in damaged. I used a thread file to straighten out the lead-in so the lug nuts start easily.
The studs protrude the most on the front, 15mm, spacer at about 27.5mm.
Replacing the existing studs is a pain. The existing studs will reside in the well between the thru holes on the older vantage wheels but the 2009 wheels have this cavity filled.
The back of the wheel shows how these are filled on these wheels.
The setup to drill. I’m using a really long center drill to spot each location. I just need to be careful not to drill thru the front. I drilled 1.15″ on the rear and 1.13″ on the front which left 2mm clearance.
This is the drawing I used for the modification to all 4 wheels.
At some point I’ll paint these holes to prevent corrosion.
Installed December 2019