I am rebuilding a traxxas revo that someone gave me, and I noticed that the antenna wire was only an inche long,way to short to be in the 27mhz range,can anyone tell me what the proper length should be to be in spec with 27mhz?

The length can depend on the particular model. The antenna is 23.5 inches on my Traxxas model 2015 27 MHz AM receiver. That's probably close enough for other Traxxas 27 MHz receivers.

Thank-you Howardcano.