3. Have stuck valve on #4 cannot get head off. Managed to pry up about 3/8". Cannot get any looser. Just took off nuts. Studs are still on. Should I remove studs? if so, how do you remove them?

Sorry to hear of your struggle.

Whenever a head moves any amount at all, it usually will continue its upward movement by even persistent prying. If you decided to remove the studs (which is a very good idea, and is what we do on every engine we dissemble), you'll have to spring for one of our stud removing tools from our online catalog - listed in with our "Specialty Tools". These tools grip the tops of the studs by clamping around the threads using a threaded collet which doesn't damage the threads. - Updated: January 10, 2004