Tranny question with stall and T Brake
 

I have a 69 camaro that has a tranny brake, but I didn't connect it. It was not needed to engage for reverse. I now have tranny fluid all over the floor and it is difficult in reverse. Before, with a different rear end (used to have 456 now 3:55) never an issue in reverse.

Any idea if the 2 are linked? I'm a tranny idiot.