32mm vs 34mm is about the size of the Venturi, the hole where the air flows through when the slide is completely open.

34mm will flow more air than smaller Venturi 32mm

 

What I don't get is that the inside diameter of the carb output as well as the diameter at the smallest point of the venturi is still 34mm.

 

What numbers are you looking at that make you think it is 32mm?

 

On the output side of the carb on the flat section is a 32 stamped into it. When I look up pictures of a VM34 vs a VM32, the V34 seems to have a much shorter input neck than the VM32.

 

The 30-32-34mm mikunis are hard to distinguish because they are basically the same carb body with all the internal parts like the slide etc. also being the same.
The Venturi is a bear to measure because of all the tapers.

Like you say the VM32 is a little longer from inlet to outlet side compared to the 30 and 34. (102 vs 93mm) That's the number to check.

Lots of detailed info here
https://www.mikuni.com/pdf/vmmanual.pdf

 

What’s the actual numbers stamped on them? I have found 34s to be a much more common carb size than 32, surprised someone would change them, especially a matched pair. Anything is possible.

 

The number stamped on each carb looks like a 00 stamped above and a 32 below it.

 

I have found the #'s stamped on those pads to be pretty useless! they don't seem to mean much I just measure mine to be sure of course I have enough carbs kicking around that I can compare to known 34mm carbs, 32 mm is way more rare than 34 mm in Doo world!

 

Seems weird, not the sleds I usually work around but maybe those carbs are not even of a Skidoo, but another brand.

I can see that if you have no idea where a carb came from, but otherwise works well to match up in the specs book.

 

Have you checked your plugs? I can understand the want to have the correct carb but if it is infact a 32, it'll work may just need some minor jetting adjustment. It's possible to run a wide range of venturi sizes as long as jetting is correct.

 

Yep I have a couple of 5500 Blizzards right now one has the stock set up with twin 34's one has twin 36's and my Everest runs the single 36 mm they all run fine there is really little difference between them. I will say the 5500 with the 34's has a bit more snap than the one that has the 36's but the one with the 36's seems to pull a bit harder up top but that may just be my impression and the Everest with the single 36 is great too starts easy and not a fussy engine at all pulls hard as well. All that to say once you jet them in you could run pretty much anything I guess.