Car and Car Conversions ran a series of articles on this procedure. Basically you strip the carburettors from everything which is not airflow related and fill up the holes for jets etc. to make it as smooth as possible. Then you weld the injectors into you inlet manifold at the right angle towards the inlet valves. Basically that is all. Then you need to set up your computer to do the hard work on the injection with its throttle position against fuel flow calculations. Some hours on the dyno and you're the man.

I could try to explain more, but I don't know it off the top of my head. Search for articles by Dave Walker or ask him at http://www.emeraldm3d.com/. As far as I know there still are back issues available for CCC magazine. There also are a lot of pages of diy efi systems. Google can tell you where. PM if you want specific info and I will try and locate it for you.

Arne