it's just because the v6 is so much heavier in the front. You certainly wouldn't want to put coilovers intended to hold the weight of a 4cyl engine, on a V6 Accord. You could however put the coilovers intended for a V6, on a 4cyl Accord. Some manufacturers sell the same equipment for both V6 and 4cyl.
ummmm it'll fit... i believe we've had this discussion already, cause the Tein SS V6 and i4 has the same model number, and I know for a fact that my friend bought his coilovers from a V6er and installed it on his i4... http://www.tein.com/honda.html so rest assured, it will fit,
So it will fit, but will it perform any differently. I mean they are the same product #, same spring rates, etc. I dunno why it wouldnt work. The only thing that is different is the min/max ride height, is that due to weight difference or is there another component im not considering??