fiki, please don't think I was indicating you didn't know what a TB was for. I just didn't understand the engine braking element of your question. My 350TH and Powerglide I used, which is now waiting for another project both are reverse pattern and both have engine braking when letting off the gas. In fact, at the drag strip I don't hardly have to use the brakes because it slows down enough for me to make the turn off. There might be some reverse pattern, TB setups that don't have engine braking. I am not an expert. I just happen to have a couple transmissions with Trans Brakes.