Well, I built this truck a few months ago, but quit playing with it until this week.
A friend of mine when I worked in Louisiana, had a Slash 4x4, and so did I. Then he sold his Slash, and we both bought E-Revo Brushless trucks. Then he went out and bought himself a SC8e, (1/8 scale brushless short course truck for those who don't know), and kept bragging about how it would put a hurting on my Slash. Well, he sold me his E-Revo, and I decided to convert mine to an E-Slayer, so I could hang with his SC8e on the 1/8 scale platform.
Here is that story:
Truck started off like this, as a brand spanking new box stock ERBE.
Then, as an ERBE, it got some of the usual upgrades, RPM arms, Summit driveshafts, KD center shafts, Pro-Line 3.2 Mashers on Maximizer 1/2 Beadlocks.
Then, the big changes began. Slayer Pro 4x4 A-arms, bumpers, toe links, TRX aluminum pushrods, Tekno R/C swaybars, stuff like that.
For the diffs, in order to make it bombproof like that SC8e, I lucked out and found a set of RCM diff cases. These are cases, machined to fit inside the stock Revo/Slayer bulkhead, but hold a 1/8 scale diff. I chose Hot Bodies d8 diffs, and then swapped the stock 43/10 spiral cut ring and pinion, for a closer to Traxxas ratio 31/10 straight cut ring and pinion. I filled the rear with 5k fluid (IIRC) and 10k in the front (again, IIRC).
i also installed an E-Revo center diff, but first, replaced the stock diff cup and spiders, with those that come in the E-Revo front and rear diffs. It has the metal cross brace and spider gear retainers for more strength. I filled the diff with 100k fluid IIRC.
For driveshafts, I chose to use Summit shafts, and cut them down to length so they would fit.
I tossed on some taped Pro-Line buggy sized Bow Ties on some AKA buggy wheels, but hadn't changed any of the suspension settings from when it was a Revo.
She sat waaay to high, and handled like poo.
So I got to tweaking, took out a lot of spring pre-load (still running ERBE stock springs), set up the caster/camber/toe how I wanted it, and she got to handling A LOT better.
Also put in a single JR 9100T steering servo, aluminum steering arm, heavy duty servo saver, Castle motor fan, and a new receiver so I could use my Futaba 3PKS radio.
MMM/2200kv equipped on 4s Lipo, geared 21/40 Mod 1. (38 mph with that setup) And that's how I ran it for a while against that SC8e on my buddies big backyard track. And it held it's own. Hung right there with it.