Here are some articles that I frequent pretty often. They have helped me out immensly in understanding the Volvo Head swap, as well as how the EEC-IV computer works and how to tune it. Hope these help!
The Famous Merkurtech Site for the Volvo Head Swap
This is a far better site for the Volvo Swap. Has more detailed info and is more of a step by step process.
40 Bob's web site. Has gutted and polished intake and exhaust manifolds as well as a couple other interesting parts.
This is a PDF about the Ford EEC-IV system. Its a collection of info gathered over time all compiled into one document. Really interesting. Also has some info on tuning the computer.
A page with links to almost anything you could want to know about EEC-IV systems.