They are both the same as far as I know and I put a v6 one in my 1st gen which really didnt improve breaking power that much. Once I found the right dual diaphragm booster for my truck my braking got insane. I barely touch my brake pedal and it stops faster then before I changed it which took some foot power to get it to slow down. Tho ive also switched to FJ80 rotors and V6 calipers. If your looking to upgrade ur setup and its a second gen or newer then get the master cylinder and the dual diaphragm booster. It will blow ya away on the diff and they can be found all over the picknpulls around here.