Depends...do you want to drive it this weekend? If so, replace that one spring and get back on it. What part of the country do you live in? That would make all the difference for me. I want my car running RIGHT NOW!!! because of the weather. In a couple weeks, it will be too hot to work on it, THEN I would have the work done.
I'm in north carolina. I'm pribably going to replace the one valve spring and get a set of aluminum heads later on this year and swap the gt40s on to my maverick. Anyone know if e7 use the same valve springs as gt40.
The springs have little to do with the heads. More to do with what cam they are being used on. They may be the same size (pretty sure they are), and might fit, but they may damage the cam if they are too stiff. Ask me how I know this...