OK... I thought sure I read somewhere about swapping them... maybe it was EK to EG tho... dun remember, wasn't really paying attention to it when I was reading it...
Either way, I was wrong... thanks for correcting me Tony.
According to RockAuto's part numbers, no, the ball joint won't swap over either... so you're pretty much screwed there.
If you're worried about the price, try RockAuto.com... they're pretty good on prices.
Tony, by the way.. if you're getting lowering springs, and you get them from an EG.. if they are preloaded due to being on a smaller (stock) strut assembly, they won't lower your car at all, they'll just stiffen the ride.
Preload occurs (I'm sure you know this, but to clarify) when the spring is longer than the area that it's being placed to support... Stock springs are always preloaded, which is why it can be so dangerous to remove them.
I'm not sure on the exact length difference, obviously, so lets just use this for a "for instance":
If the EG struts are 2" longer than the EF's, and you got 2" drop springs for an EG, then put them on an EF.. they should fit just like the stock springs... no preload. Obviously, with 1" drop springs from an EG, they will have 1" of preload, which, depending on the spring rates, could signifigantly stiffen your EF's ride.
With these same figures, if you got 3" drops for a EG, They would (again, in theory) drop your EF 1".
All of these figures are probably wrong based on the sizes, but you get the point.
Now... with that same principle, would you then be able to "cheap out" on lowering your EG ride by getting stock springs from a EF? Or even using the stock springs/struts from a EF, and using the EG's forks?