I am currently looking at a 2006 XF 700 Sno Pro and was wondering if they are fine the way they are or if there are any must haves that should be added after that were not stock.

tunnel supports are a must . Thats pretty much it Crossfires are great sled good luck

As the Guy states great sled to start with BUT........
to get this sled to run like its capable there is a list of improves that can
be done.

1.Since you have the sno pro the only rear suspension (to do) is to put
the larger upper rear wheels in, this helps with the TSS link interference
look at it, if stock most likely polished where it has been rubbing on the track.

2. if studding you need to add the tunnel protector strip (inside)

3. if it is a diamond drive you need to add the Shift assist allows the secondary
to back shift and improves the overall performance in trail and while boondocken

4. tunnel supports are a good piece of mind insurance plan.

5.Clutching is for the most part OK but the thing will fly if adjustments made.

6. I replaced my skis with Powder Pros improves turning.

7. Oil pump adjustments the sled is very rich in the oil dept.

Now if you are only going to ride 500 miles a year this sled rocks out of the box!!

But if you race with your buddies and ride hard
in this forum start looking back in Dec and Jan of 2007-8 and there are the measurments
and part numbers and gobs of tuning information.

I am now extremely impressed with the power and handling of this sled.

Soulemann

Knee pads.
Aftermarket deflection adjuster.

the best mod i did on mine was a 1.7" track! i don´t se any reson to keep the ripsaw.

injektor perfector makes it a litle more crisp on top.

chutchkit is nice to have inkluding shift assist.

tunnelsuports may be a god investment.

remove the cupling blocks. (depending on riding style)

I would also suggest a handlebar riser since I like to stand a lot. If you stud it you may need additional tunnel protection unde the gast tank. I sure did and all I used was a lightly used hyfax.