I have the older 3906 Emaxx too - this what I did to mine to make it handle TechnoNeu 1515 1Y, Quark 125b esc and 4S. I changed to 3.3 bulks, drive axles, A Arms, strg knuckles and turn buckles. You can use stock A Arms, but they have to be clearanced near chassis to clear the 3.3 axles u-joints. I upgraded trans with UE idlers and UE drive cups to let me run UE TI center drives. I keep it in 2nd - 1st is ridiculous, almost instantly on the lid! Last and crucial was a set of 16.8Emaxx diffs. A wheely bar and mines been good.
This sounds like a lot, but I got it all off Ebay and in one afternoon made the upgrades. I switched to a set of Tony's alloy steel screws while I was at it and its been a blast ever since. I have 2 MMM, but they're going into other projects - I believe my upgraded Emaxx could run it with out probs.