Chris,
I'm not Dave.................obviously.
I don't think your car is to light.
I will offer you this info however:
I would play a little more with your diff oils. Try lightening your rear oil up a bit and then maybe your center a little. If your running 3K in the rear DON'T be afraid to try 2K or 1K. Same with the center diff. Remember, one change at a time. DON'T do both at the same time. You should notice a BIG difference.
While there are MANY other adjustments that you could make to the geometry of the car, I think the diff oils would be the easiest and probably the most noticable for you as well.
Another point for everyone here that may be somewhat new to RC or whatever: driving styles, engines, track surfaces and tires play a HUGE, HUGE part in set-ups. Don't freak out if David's or Gene's or Greg's or My set-ups or someone else's set-ups don't work for you and YOUR condition's perfectly. You may be a hammer and trying to run Davids butter smooth driving style set-up or your may be butter smooth and trying to run my set-up. Point is, it's NOT the end of the world if you have to change something that doesn't fit you. XRAY has included probably the most informative set-up info in the back of their manual. Use that information to your advantage!!! Just do a couple of things;
MAKE ONLY ONE CHANGE AT A TIME!
--and--
WRITE DOWN WHERE YOU STARTED SO YOU CAN GO BACK IF NEEDED!
I'm sure David will be on here soon and have a comment for you as well.
For what it's worth,
Mike