As others have stated, you need to run at least 105 springs with that cam. You can run a new stock timing chain/dampener also, but you should raise the idle to prolong chain/dampener life. Some say 130 springs are the way to go in order to take full advantage of the xp's high rpm power, but 105's will be fine unless you want to squeeze every last bit of hp out of it.
You may also want to consider the s1x cam. It is very similar to the XP, just slightly smaller with more low/mid range power. I have run it for two years and I love it. It's a great street cam. IMO, the s1x is even more friendly to a stock chain setup with 105's than the XP...
