First off, Here are two good write-ups with photos on how to re-drill the Hubs for 6-Lug conversion.
Drilling the Hubs
You will need the following parts:
1. Eight more 1.25x12M thread wheel studs. (Found at any parts store)
2. At least one 6x5.5 lug wheel for marking new holes on the Hubs.
3. Center Punch/Transfer Punch.
4. 14mm or 9/16" Drill bit.
5. Also a smaller 6mm or 1/4" drill bit to start the hole is good.
6. Preferably a Drill press, but a normal Variable-Speed Electric Drill can work.
7. Plenty of oil to lubricate the drill bit.
8. Angle Grinder with Grinding or Flapper Disc to smooth bures.
9. A big Hammer and/or Bench Vise.
10. And preferably a chunk of hard wood for the Drill bit to go through.
11. And of course, all the parts to remove the hubs from the car.
You will start with your Stock 4x140 wheel hub. Grab yourself a Hammer and then a Block of wood.
Place something under the hub next to the stud you want to remove, but not under the stud.
Use the chunk of wood between the stud and the hammer to stop the hammer Mushrooming over the threads.
Continue to hit it till it puts out. You will then have this:
Now you will need the 6-Lug wheel.
With the two remaining studs in your Subaru's hub, bolt it to the 6-lug wheel like you would if it was on a car.
Now you should be able to see exactly where you need the new holes.
Should look something like this:
Line the Transfer punch up as close as you can get it to the center of the hole in the wheel.
Transfer Punch Link:
A transfer punch will easily and inexpensively transfer the center of the hole to the proper point on the wheel hub.
Tip: Try looking at it from other angles to see if it really is centered.
Strike the punch with a Hammer, it may bounce and put a smaller mark not directly in the center, make sure the mark is centered before drilling.
Repeat 4 more times per Hub.
Now take your 1/4" or 6mm drill-bit, take it slow until it bites and continue to drill.
The center punch mark eliminates drifting the drill-bit may do while trying to drill the holes.
Tip: When drilling the holes, if your using a power drill, make sure the drill is completely vertical, otherwise your studs will stick out all over the place and you'll never get the wheel on. If your using a drill press, you should have no problems at all.
Now that you have the 4 new holes drilled to 9/16" or 14mm,
Grab your Angle Grinder and flatten the back of the hub where the new stud will go.
This is to make the stud sit in place without rocking around (which causes wear and may lead to the stud splines failing.)
Place the hub on something hard. Put the new stud in place. And tap the new stud in until flush and seated.
It should look like the picture below now.
Tip: Some folks like to add a bead of weld to each stud to keep them from walking around incase they do not tap in snuggly.
Here is another picture showing the Stub seated flush agains the Hub, this is the Rear Drum.
Repeat all steps until you have 6 Lugs per wheel hub, and you are finished!
This is what it should look like:
Now with Wheel Installed:
Common 6x139.7 Wheels/Manufactures Chart:
Edited by TheLoyale, 14 May 2012 - 11:45 PM.