These heads bolt right on, and since they came out of a 2000 - 2001 Mustang
GT they also have the high performance cams in them.
If you like these heads, check with the seller, he might also have a PI intake
manifold for your stang.
Also, make sure that you get the cams, and he doesn't take them out.
The only thing I am not sure about is the bolt pattern of the valve cover. There are 2 different styles (8 bolt vs. 10, or something like that)
If you don't feel comfortable with the installation, ask your shop (dealership) FIRST, how much they would charge you for doing this job. That way you can estimate the costs pretty acurate.
By the way, 2V PI heads are so common, you will always see a set on ebay. If you want to think about it, just take your time.
There is no reason to rush.