I will race SC 4wd mod with a SC10 4x4. Is the best motor a 540 or 550? How many turns?

You'll get many opinions on this one, mine is pro4 4600kv 540 can if ROAR rules (or the Brazil equivalent) are a concern or tenshock 4600kv 550 can if it's just for club races. 13t pinion.

Yup, like mine as well. My truck is very planted now, even outside with no traction.

I'm at 10,000 but I had done that to try the center diff. I think I need to go even less now with the Exotek hub.

people are saying 5-7k with the exo hub

im running the Reedy sonic 4.5t 550 motor in mine. i ran the pro4 4600 i thought it had a little to much power on the bottom end. just my $.02

Your running the Pro4 4600kv motor now Chris?

did you measure with calipers? that's sounds like A LOT.

ok, the supplemental instruction dont show the shim between the outdrive and the diff and i cant get the .5 to seat correctly with the output shim in place. Do I remove the old internal and external shims?

I gotta say that I'm a pure loving nitro nut. Decided to get into the Corr class and purchased myself a used SC10 4x4. I like to be just a little different so really chose agaisnt the Losi as that seems to be the most ran Corr truck in the history of this class.
Gotta say that this truck is ok but nothing close to awesome in my opinion.
1. No need to set drag brake. The drivetrain has it built in.
2. Working on this truck is a total nitemare. I can handle it but if you need to change most of anything at the track, it would be awful. As a secondary class, it could be a bit easier.
3. To many slipper adjustments. For performance, you tune with fluid, not pads and springs. The VTS made a great improvement but gesh.
4. I'm not a fan boy nor will I jump up and down for any vehicle made but I gotta wonder what in the samuel hell the designer was thinking on this one.

She seems to drive pretty well and I have been enjoying the results from it but I can see an easier way to build a corr truck.

I left mine at 30k and I don't notice any problems (but then again, I also didn't notice much of an improvment when I put the locked clutch in).

What do I stand to benefit by lowering the diff fluid up front now?

The only shim you use is the .5mm shim under the sun gear...Everything else gets removed. For me I tried .5mm and it was too much, .4mm seems to be the sweet spot and my housings and gears were used when I tried it so its not about the parts being new.

I guess wit the exotek locker, the truck pushes more, just like adding in the c diff. So you go lighter.

soooo. I just spent 1.5 hours changing the shims in my front diff...........I will never change diff fluid at the track, this is kinda retarded. With practice I am sure I would get faster and with a power screw driver even faster. But wowzers. Anyway. The .5mm seemed to fit fine. But truth be told the original shims seemed pretty tight. No metal in my diff and near excessive wear that I could see. The .5mm shim fit fine. Maybe a tad tight. I think .4mm is probably the sweet spot. but the .5mm went in easy mode. No binding that I could see and the front wheels spun free without the belt attached. I am not motivated to do the rear diff tonight, I will do it when I change the diff fluid, lol.

Read above!!

Lol. I said I would get faster with time lol