What is the length of front and rear wheel studs. Are stud lengths measured from beneath the 'head' of the stud or does the stated length include the thickness of the head ? Are both front and rear studs available approx. 4mm longer than standard length ?
Fitting rims which require longer studs - new rims are 4+mm thicker at the hub so will need longer studs - 10mm extra would be fine. Do you know if these might be available in Australia (front & rear)?
You want 18mm of thread engagement so depending on how much thread you still have to work with you may not need the longer studs. Otherwise Nismo do 60mm extended wheel studs (which I use on my car) that you should be able find in stock somewhere (just jap etc). Just be aware that the knurl is different front and rear so you'll want to confirm with the retailer that you are purchasing the correct part for each. I have a writeup on how to fit them at https://rgsperformance.au/pages/how-to-change-rear-wheel-studs-on-your-nissan-300zx-1 If you're using a closed type nut you may need an extended nut to accomodate the extended stud so shamelss plug I'm selling these still new in box https://aus300zx.com/index.php?threads/nismo-50mm-wheel-nuts.339190/#post-1487834
Like rob260 said just jap have the 60mm nismo it stock, or you will need to chase down to 50mm. I would think you would need the nismo long nuts on the 60mm or the opened ended nismo. Most people say you can run 5mm spacers without longer studs. How did you even work out the wheels are 4mm thicker?
Thanks Rob and Morboost - in answer, I ground down a standard wheel nut so that it was no longer a closed nut. Then held it in its normal position on an OEM wheel. I inserted a vernier calipers in through the back of the wheel and through the thread until it reached the far end of the ground down nut . Took the measurement then did the same on my new wheel - difference 4+mm. If interested, new rims are one of the Simmons range.
