well since there is no help here I will post what I have learned for the next person.
1. What weight Diff oil should I use in the whole car?
Depends on what you want to do. For the Rally cars you can leave the Stock 50k WT in the diffs both front and back. You can go down to something thinner if you want but the change isn't huge.
2. What gear ration should I use for using 3s and 2s batteries?
I have decided just to use the 31 tooth pin gear that came with it with the stock Spur gear. Haven't tested it out yet but I'm sure it will work just fine for drift and race.
3. I have heard something about shimming the diffs, anyone have any information on this?
The 1/16 cars have a know issue of the diff gears having some space in them and can become lose, which will cause wear on them. This is where you get the clicking nose in the diff. It is more common in the Slash and Revo models and in the older diff cases. The new Diff cases have a screw that goes through the two sides to hold it together better. If you are just running a rally on street or drift then this won't be as much of an issue especially if you have the newer diff cases. If you have a revo or slash model though it is recommended to shim them early to prevent damage later. You can find shims here
4. I have 70 wt shock oil in the shocks now but is there a better weight to use?
For racing 70WT is recommended (The Traxxas brand, not sure how that compares to the Losi Brand) for both Front and Back and to use 4.3 Springs (TRA7342
) in the back and 3.4 Springs (TRA7341
) in the Front. This will help the car not to flip in tight turns at higher speeds.
5. Where can I find some shorter PushRods or adjustable PushRods for the car to make it sit even lower?
I was meaning to ask about the PushRods not the A-Arms. I have heard that Integy is not the best Brand to get parts from but I think these will be fine on my Rally. PushRods
These are adjustable and should allow me to lower the car even more so I can control the ride height better. You can get full sets of adjustable Pushrods and Toe links but I already had the Toe links so. Such as these- Turnbuckle Tie Rod Set
This is what I have gathered and learned while looking around on the web. I will be sure to post pictures and more information as I get it. I also plan to post a full detail list of everything I have done to the car so if someone else is looking for help they will have a starting place.
If anyone has any suggestions or corrections please feel free to fill me in.