yeah, I might have to run 100k in the front then and 50 in the rear since I'll be racing my truck and not climbing or the sort.

Maybe even like 60 in the front and 40 or 45 ish in the rear. Depending how much resistance you are looking for.

The thicker silicone that you use the easier it is for your truck to come to a rolling stop w/o using the breaks. (freewheeling)
Thinner silicone will allow your truck to roll easier, thicker silicone will give more resistance.

I may be wrong but I would think that when the truck is rolling straight ahead that the internal diff parts (the ones affected by the oil) wouldn't be turning at all, so the diff oil wouldn't affect stopping.

so when I do my diff mod do I need a kit? or can I just pop off the 3 screws, clean out all the old grease and fill them up with the silicone and lock the screws back down? any kinda of gasket seal needed to prevent leakage or should I just check them every so often to see if they need to be refilled?

I did my savage diffs and haven't had to touch them since last year.

and also how much am I putting in do I level off the fluid in half the diff cup then cap it? or half way? etc..

All you need is the oil. There's a gasket in the ring gear and an o-ring in each outdrive to seal it. I just wiped out as much grease as I could and used kerosene to clean them out completely. Fill them up to the top of the bevel gears... some will probably squeeze out when you put the ring rear back on.

i just finished reading a couple of threads, i am a newbie so bare with me. i changed to alumi diff cases per to everyones suggestion (good thing to because it was cracked like a coconut) to change to silicone diff oil i am cleaning out the diff housing and putting the oil in there and not the diff case?

Yea you got it, Oil to the Top of the Gears(diff housing) whatever its called, Then some grease on the the out side Ring Gear.

Thanks Sublime, would it be alright if i used 50k silicone diff oil on the outside ring gear?

I don't think Oil will stay there? I uesd some Black Grease.

I think the oil is to thin, and would be thrown off. I just had some associated green slime handy and used it on them.

Sometimes it may benifit you to do a little planning ahead. I installed my RPM A-arms at the same time I did the alum diff cases..This saved some extra time in that I didn't need to undo parts a second time for an installation. Hope alittle planning will simplify future remodes. DBM [8D][8D]

For racing on really big track I run 50000 diff fluid, but on tracks like the Nito Maxx challenge I use 10000 diff fluid front and rear.
Adam Drake gave me that formula and really works. I hope this helps