Will I get away with 5mm wheel spacers on the standard nuts/studs. Running standard prodrive 18" wheels with brembo brakes.

 

No, not enough turns on the bolt threads. I can show you the problem at next weekends meet

 

It would be safer to get some hubcentric ones, with extended bolts.

 

3mm is as thick as you can go and still get the min 7 full turns required on the wheel nuts.

 

Ok sounds good. Do the bolts sit in from behind the hub? And where is the best place to buy or is it 6 of one and half a dozen of another?

 

Depending on size....

Thinner ones, like 5mm, you would need to knock the existing studs out, and replace with the longer ones.
For thicker spacers, they bolt directly to the existing studs, then have new studs of their own.

H&R do good spacers.

 

Yes please.

 

Would you notice a 3mm spacer on the look of a car??