These are the nuts that are used to Bolt the Exhaust manifold to the head, and in a YD25 motor they are used to mount the Dump pipe to the Turbo
The studs and Nuts get affected by the amount of heat around the turbo manifolds - we recommend replacing them when you have the manifold off - as it's a very painful exercise to have the nuts come loose after a short period or have the studs snap as you are tensioning them up.
Depending on the engine there is a Different Qty Required
ZD30 x 8 for head to Manifold
YD25x 8 for Head to Manifold
YD25 x 3 for the Dump Pipe
VQ40 x 12 For Head to Manifold
In Some applications the flange on these nuts may foul - we also carry them in a non-flanged version
We also sell the Studs separately or in kit form for different models of vehicle - so search our other listings for these kits
