...and I guess I was supposed to read your mind about this since you left it out in your first post?
It depends on what you have now.
No. You need to tell us. what you have. Year engine and casting numbers.
I have no idea. Does it use oil? Does it make noises? If it runs and does not skip or burn oil then there is likely nothing wrong with them. If you're asking if there are better heads you can run then, without knowing what you have now, that cannot be answered accurately. There are several things you can do without tearing into the engine to make it much better....if they have not already been done. .....and smartin off somebody trying to help you when you've given limited info isn't a good start.
Glad you're a newbie trying to learn. I'm not a newbie and I'm trying to help you out by answering your questions that you threw out with very limited information. You can add as much as 30 or so HP and never take a valve cover off, much less change heads with a few tricks. Best thing to do is follow the advice here. Find out what you have now and let us know. Head casting numbers will be helpful. Which 340 manifolds? There are two types. Early and late. The early are the better ones to have. Casting numbers once again will be helpful.
