I don't know what you mean by break after a gallon of gas, like you drive it for a gallon, then all the parts fall off and break in half?
If your askin if a part will break by the end of the first gallon the no one can answer that, it all depends on how you drive your truck, if your goin full throttle, and hit somthing head on while still on your first gallon, then yea chances are you will break a part... if your talking about the engine life, most people get around 6 or 7 gallons before they get a sleeve pinch, or new piston and sleeve. when you first start jumping you will probably break parts on either truck, but after a while you will get used to jumping and knowing how to correct it in the air... Don't know which has a better engine life, but again its all about how you take care of your car, how you tune it, and if you do after run... I think the rustler would have more hop-ups than the mt2, but really the only place you need for hop-ups for the rustler is www.rdracingproducts.com they sell really good alluminum and carbon fiber hop-up parts, and since the rustler has the same engine as the t-maxx you could also get a ton of powerfull drop-in engines, and cooling heads, etc..

I don't know why you are asking if you put better shocks on if it would be a better jumper, maybe because you hear people say the plastic shock caps somtimes pop off? if thats it all you have to do is buy some alluminum shock caps for the big bores...

sry for the long post... I think I answered everything though [8D]