[JL audio guy]

I have a 1964 impala with a 355ci and 350 trans and im wondering why my transmison wont up shift ...if i do it manually it works and it down shifts great so what should i look for ....fluid is full and clean ,torque converter is brand new too..some ppl told me it might have a shift kit that you have to shift manually but i dont really know thanks for your help

 

[httnmrtt]

With a new torque converter, that tells me the transmission was out of the car recently. Double check to see that the shifter linkage was installed correctly. The Turbo-Hydramatic 350 was GM's premier automatic for years. Check you vacuum modulator and the vacuum line going up to the intake manifold. If the line is disconnected or leaking, it won't shift properly and if the diaphragm in the vacuum modulator is ruptured (indicated by transmission fluid in the vacuum line) the transmission will not shift at all.