I wouldnt put aluim arms on it....as far as the engine, yeah it should be a direct drop in...

guess I didnt get your entire first post (sometimes I have selective reading...lol)...your servos should be fine fer the most part....however I would conceder this servo for the steering
http://server.sohouniverse.net/~himo...p?id=1144&=SID
its a metal gear servo...its faster and more powerfull...like I said..not a havta but I like to put a good servo on the steer...

also I dont know which batteries your using....if your not runnining rechargeables I would diff do that....and if your running just AA batteries fer the reciever make sure wrap a rubber band around them or tape them in...I like 5 cell hump packs myself....also dont know if your aware of failsafes...you will diff want one of them

sorry if yanno some this stuff...just tryin to cover all the bases man..lol