I just bought a 1994 Z28 Camaro with the LT1 and I am having trouble with the tranny not shifting right. when I am going between 35 and 55 and thentry to get on the accelerator hard the RPM"s go up high and sounds like its slipping and I let off and peddle it a little and it will go back to pulling again but when it tries to kick down into lower gear does it again ????? I already went and bought another tranny but i need to know why or what is causing this before i install the other tranny.. Can someone please help me out???

 

From the very little information that you have supplied, It is most likely slipping because the transmission is 27 years old and it is time for a rebuild. Give more information and maybe we can be more precise with a diagnoses. Has the trans been rebuilt, how many miles is on this trans, if rebuilt was it a stock rebuild?