if i buy a differnt radio for a nitro rustler would i have to get new servos???

NO

It depends if you buy a controller and and receiver and its frequency is FM and the servos are AM then it wont work make sure when you switch controller and receiver that the servos are the same frequency. i had this problem my LHS sold me a FM servo when my receiver was AM

NO

yes it is when i switched over to my FM futaba reciever the problem stopped.

no i am asnwering his question

well the radio is a fm 27m

well then yes you wuld have to get new servos, BTW traxxas servos are POS

o haha sorry about that Nitro Rustler Racer

Standard servos don't care whether the radio is AM or FM... as long as they'll plug into the new reciever (and the Rx modulation and frequency match the Tx) they should be fine. It's only with some of the higher-end servos that you have to start getting specific kinds.

i tryed putting a new JR servo into my stock RC10GT reciever.

ncgrunt has it right, the main thing to worry about is type of plug.

usually you can just trim the servo plug, my JR servo plugs into my novak receiver just fine and my futaba servo plugs into my JR receiver pretty nicely, too

I thought you could do that too (I heard someone else mention that before). I didn't want to say anything in my post since I only read it once.