Thermostat housing stude size?


I have installed the intake and fuel rail…and ofcourse the thermostat housing is still sitting on my bench. I bought a bolt that the original nut threaded onto and it felt fine however the bolt would not thread into the head. Does anyone know the correct bolt size and thread pitch to replace the upper stud for the housing? I thought i had read it on the forum sometime ago but cant seem to find it now.


8mm. Not sure what the thread is, but it’s the common thread. I’ve not seen an 8mm bolt in any other thread.

The threads in the head could be buggered up. Easy for that to happen because the AL is so soft. Might want to pick up some metric thread chasers and a metric tap and die set. If all else fails, you can threadsert it.

One of the tstat holes on my head is buggered up. I just go gentle on the torque and use blue locktite.