I believe the Kaiser has bolts as opposed to nuts on the cylinder head. What I normally do is hit them on the top with a ballpeen hammer a few times before I take them out and I've never wrung one off. Of course, if your car is very old, had a leaky gasket etc. there could be a lot more rust on them. I'm sure others will chime in here with their suggestions methods. I do believe the bolts are still available from Dorman - someone on here will know so await some more replies.