I ran a gear diff with Asc black grease and doubled up on the 9mm diff washers (also helps lock up the diff) on Friday night...
I was the only one not running a ball diff on low traction carpet (brand new +) and I was left behind coming off every turn. Hell I lost 6 ft right off the line due to wheelspin. I will be going to a ball diff as soon as I can be bothered to split the chassis again.
The hardened pinions (from F201) are a much better choice than the cheaper alternative they last much longer.
I run the short blues up front with 70wt oil and red springs with 40wt in the rear. 4 o-rings in front shocks, and 2 in rear (on shafts inside.
As the track works in, I will put the sway bar back on the front and go back to Type A's all the way around. Btw this is with an M03 running:
Full bearings
TL01 suspension shafts
Universals
Aluminum front hubs (adds alot of weight but saves on breakage)
Lightened kingpins
The low friction aluminum bodied shocks (cheap)
5mm ride height (rules....)
Ti turnbuckles (not tcs legal)
Also, the servo mounts are drilled to permit 2 screws on each side of the servo which prevents the servo mounts flexing so much. (not sure if this is legal for TCS or not)
At TORC its often an M04m that cleans up, (
http://rcontario.com/rcorevms2004.html)well when he shows up anyways +) and it has all the hop-ups.
Only rules we run are the silver can, and a 5 mm ride height.
We don't race them often but when we do its a blast.