RE: Help ID this tmaxx
Your truck appears to be the 4909 model.
You can fit the 4908/7 transmission in it but the output shaft is 6mm instead of 5mm like yours.
You will have to adapt the center shafts to fit the output shaft.
Yours truck appears to have the Forward only converion, if so you can install that output shaft in the 4908/7 transmission and the center shafts will be a direct fit.