[KTL]

The Carrera 3.2 intake uses a M8 x 35 stud on the intake side of the head

999.062.010.02

Also the cylindrical-shaped female inhex nuts are recommended to use because the area around the intake runners is tight for regular hex nuts 901.111.271.00 x 12 nuts. These also use a fat spacer washer (~ 2.5 mm thick) under them so the hex doesn't get too shallow on the threads 999.025.152.02

The inhex nuts and fat washers aren't an absolute must, but I will say they make tightening the intake a lot easier. Plus the intake is known to get a little loose sometimes, so its nice to have cleanly installed fasteners with minimal interference. That said, I cooked up some shaved conical spring washers to use under the nuts to help maintain tightness. I can't say if it really made a difference. Just pointing out that I was able to use something other than the factory fat washers with the inhex nuts.