when it comes time for a new engine for well any type of nitro powered vehicle are all engines the same as far as what fits and what wil bolt to your particular chassis? for instance i have a 2.5 rusty and when i need to buy a new engine can i just find one with the power i want and buy it?

sure... you might need mounts or spacers... different motors will have different carbs, different carbs will lead to different linkage. pull start or n/pull start.... headers!

alot of the o.s. motors will have the same block with different parts, just do your homework and hopefully you LHS will help you

generally .12-.18 motors are small blocks and .21-.32+ are big blocks. most small blocks will be compatable with each other with minor modifications. and the same would apply for big blocks. but... some engines have side or rear exhaust which will determine which exhaust manifold you will need to buy. also some carbs as was mentioned earlier are different. some are rotory and some are slide. this will affect which linkage you will need to make every thing work. those are 2 big thing you will need to watch for when getting a new motor. the easiest swap will be if you have a small block then replace it with a small block and the same with big blocks. if you have a slide carb get one with a slide carb, and if you have a rear exhaust get one with a rear exhaust. if you start changing these things around then you will have more trouble getting it to fit properly. ofcourse there are exceptions to every rule and a dremel is a very handy tool!lol!

The O.S Tm series engines are a direct fit for the Traxxas set ups. You will just need a new header since the stock one cannot bolt onto the O.S motors.