the spring rate for the cossie is (from memory) 140lb/in and the one for the 4i is (again, from memory) 105lb/in
but the cossie spring is shorter so that it won't compress as much
the 4i spring is longer but softer so it will compress more but it should be the same ride height

as someone who knows a tad more than me about what this will do you'll probably find that the cossie springs will firm up the ride in the 4i but it may sit a bit lower than normal overall