Always remove the bolts with the engine cold and not hot helps to prevent breaking bolts and spray is always a good idea...

 

stock manifolds are like a 4 into one shorty header not the log type

 

Not so true. I always fire the vehicle up for a few min's The aluminum in the head will heat at a faster rate then the steel bolts. Then you give them a slight punch on the head, they will come out. Never had a broke bolt doing it that way.

 

A good read on the subject of headers...

GM Performance Parts LS1 Engine Header and Manifold Test - Car Craft Magazine