Friend of mine local here in the industry texted me this picture from a home he just visited. Homeowners brought in someone to finish there basement and apparently he needed to move the main flue stack. My buddy is assuming that 5ft sticks of main vent pipe is all this contractor must have believed existed, so the main stack drops much lower than the equipment, and he made up the rest from there. Classic case of you get what you pay for. Homeowner, was assured that it may look ugly now BUT once enclosed in the finished closet it will all be out of sight and out of mind! Luckily homeowner went with Jiminy Cricket yelling in their ears and called an HVAC tech for a second opinion! And here is that photo:
Name: Flue Disaster.jpg Views: 2455 Size: 95.4 KB

I edited out the orignal furnace installer pride sticker, they had nothing to do with this.

From the picture, it looks as though the B-vent piping off of the furnace is decreasing in size but it is all the same, just an illusion.