Wow! This is great news. This is an APN kit, right? If so, that means that now both Dorman and APN are providing TWO stovepipes. It would seem that they actually listened to us (and probably lots of others) who requested that they include pipes for both the older and newer engines.
The stovepipe with the larger diameter base replaces the stock 3/4" stainless steel stovepipe in lower intake manifolds built from 1995 to 1998. The stovepipe with the smaller base replaces the stock 5/8" aluminum stovepipe in lower intake manifolds built from 1999 to 2005.
I would like to think that our talks with the development people at APN and Dorman had something to do with this. Now, if Dorman would get off the dime and install a sleeve in their UIM, all would be well. Until then, the APN is gonna be the preferred choice, hands down.