Welcome.
Hum........... it seems I have been down this road.
I have a 03 RX-1 Mountain. Of course, it came with a 151 x 15 x 2" track. The sled struggled (more like sunk) in the deep stuff.
Next I tried a 151 x 2.25" x 15 Finger track. It was great in spring snow and on trails but, in the deep fluff not so much. There had to be something better?
So, in order to not have to change my drivers. I went to a 159 x 16 x 2.25 Skidoo track. The sled floated so much better that (no kidding here) I was able to ride right up to and dig out the guys riding Skidoo Revs with me.
I thought, if this works so well. Let's try a 162 x 16 x 2.5" Camo Extreme (at that time there was no such thing as a 174" track). So, I changed drivers and mounted it up. It works awesome and is still on my RX Ton today.
There are also some guys that use Polaris series IV and V tracks (very cheap on TracksUSA). They are 159 x 15 x 2.25". That way you don't have to change drivers. Look for "Kachess" on this forum.
http://www.ty4stroke.com/viewforum.php?f=13&sid=9f845aa063c9f17c371f556575f4cf6e
For the money, I'd put on a Skidoo 159 or 162 x 16 x 2.25" track and not have to change drivers. You may want to change gearing. I think 19 x40 or 20 x 42 were good choices. Also, take a look at my posts on the subject on the above link.
That extra inch of track width made a huge amount of difference in the way the sled floats. Those big heavy fourstrokes need a larger footprint to keep them on top of the snow. You can see why yamaha put a 16" wide track on the Apex Mountain.
Now, if you want to know how to fit a 16" wide on your vector. PM me or do a search on the above forum link.
Best of luck