I cant seem to get the exhaust manifolds off the heads so I can remove heads to replace head gaskets.I tried at the crossover behind the heads also.Heated the two I could reach and got them free,now Im dremeling the one I cant get the torch to or even a wrench on.This is my last step so I can get heads off and start rebuild.Been at it for 3 days solo and Imgetting frustrated.Help.954x4 pickup 3.0 V-6

 

Those are high temp lock nuts on the studs. Use a nut splitter or coat them with WD-40 and let soak.

 

PB Blaster is better in my opinion...

 

I wish I had just cut all nine of them.After dremel tool cutting the four Icouldnt free up I drilled them out and replaced them with nuts bolts and lock washers,it was ten times easier than putting the stock nuts on the other five.If I ever do this again(hope not) I will cut them all.

 

I hope you used antiseize on the threads... It will save a lot of future headaches.