The OEM shifter has two rubber boots: the big one that you have to take out to swap the shifter, then there is a smaller one below that. The way the OEM is put together you can't readily swap it to the new shifter.

Also, different bushing materials, etc. transfer gear noise differently.

 

OOOOooooooooooh, that makes sense! Thanks. Well, with nearly 250K miles on The Bruised Banana now, pretty much every nook & cranny on her squeaks or squawks now so I probably won't be biotchin' too badly about more cabin noise