Check out Crane's website, or Comp Cams. There are a lot of little things to think about with springs (I have been researching for my RHS heads and new cam). The spring has to fit securely in the valve spring pocket. There are acceptable clearances here. The springs have to be installed at a certain height to maintain correct spring pressures. This can mean using shims and a specific retainer. The retainers also have clearances regarding how their bottom sides fit into the springs. Retainers for the E7 heads will most likely not fit the Eddy's because of valve size (ex: 11/32 valves vs. 8mm valves/example only).
Now, I am still figuring this stuff out myself, so I can't give you all the definite answers. But there is more to it then swapping them over. Do some research and checkout some of the tutorials on the websites above. You will probably be able to figure out what you need.
Good luck with it.
Joe