I understand both will drive a T5 cog swapper but what are the main differences between them?

Is it pedal weight/clamping force/smoothness/max rpm/durability/physical weight/just an engineering change to piss people off...??

Cheers

EA 3.9 240mm clutch, EB2 onwards 254mm clutch,

Putting the two flywheels side by side, you won't notice any difference, I've got the 4.0 flywheel now, and RPM clutch, (should of kepted my 3.9 flywheel and clutch) .. bit heavy on the foot,

But i had the 3.9 flywheel and clutch on the ed, and yeah, did NOT use it gentley all the time, and it was fine, even with a standard ford 3.9 clutch,

Know of people who have used 3.9 flywheels and clutchs in there e-series before, and canned the crap out of them .... and they are still doing around fine!

should have asked you to begin with :p