I hadn't seen this thread when it appeared in Oct. I actually find it kinda odd. The OP has never posted again. Maybe it was indeed spam? Either way, I have really found the original Range Hood FAQ very helpful, and have emailed the link to friends cause it's such a good summary. I don't think the OP has added anything helpful to the hood FAQ, and his additions might confuse someone new to the Appliances Forum, or someone struggling with hood choices (the hardest choice for me in my kitchen!). As others have pointed out, it's odd he chose a 36" hood for a 48" range. Odd that he doesn't mention Wolf hoods in his discussion of high-end hoods, even though that's the range brand he chose. Why does he say baffles are not standard in high-end hoods - that's incorrect. And indeed, despite his contention, the greater component of noise in a hood is the airflow. You can have two identical hoods in two homes - the home with the problematic ductwork (i.e. more bends, longer, or narrower) will be noisier despite the identical motors. I think the Futuro hoods are a good brand, judging by what others have enthusiastically written on the Gardenweb about them. But I hope that people looking for helpful info on hoods in general will look at the original Hood FAQ rather than the OP's additions.

I LOVE it! Works perfectly - nice to have high & extra low output. We spent a long time going back and forth between the Dacor and the Wolf. As far as outputs, they were about the same. The Wolf was $300 more expensive. Honestly, it came down to looks. I didn't love the way the Wolf looked. And I didn't like or want the red knobs (they would have looked terrible in my kitchen). I felt the Wolf was too industrial looking. I wanted the pro function, without the heavy pro look. The Dacor is softer.

Of course you can get a 27-inch size range/vent hood custom made (even Imperial does that). But would you want to do that when the recommended size is quite different than the space you have available and want to use "as is". Copied from a Lowe's "How to install a vent hood" site (my emphasis is in caps): "Check to make sure the new hood will be 24" to 30" above the surface of the range and WILL COVER AT LEAST THE ENTIRE COOKING AREA. A 3-INCH OVERHANG ON ALL SIDES IS PREFERABLE. Be sure the wiring that will connect to the hood protrudes at least 12" from the wall. Ya-da, ya-da, ya-da......" According to recommendation above it sounds like the first/original range in your home may have been replaced with the down-draft vent model (Jennair) BECAUSE the PO didn't want to mess with getting a properly sized vent hood for a later (and then standard size) 30-inch range. At one time your house may have been outfitted with a 24" range (hence, that 27" hood over top). Personally, I don't think you'll ever get good venting from a 27-inch vent hood over a 30-inch range.

I can see your conundrum . . . the hood is just a bit on the shallow side and the narrowing of the chase as it goes to the ceiling means the body of the unit comes into play as well. It's possible that the Best by Broan, model PK22 would fit. It might be best to consult an appliance store where they can handle the installation and check for fit before you purchase. Otherwise, I'd check to see if the cabinet manufacturer has a suggested unit that would fit. Good luck!