I have water leaking on the backside of my motor

Either a heater hose, the fitting, or a frost plug.

It pours out fast as I pour it in the radiator

Sounds like a frost plug. Just have to pin point the area, and look closely for the leak. By the sounds of it, you shouldn't miss it.

OK it also ran hot two times but there's no oil in the water it jus has a knock sound to it but that sound didn't start until I change my transmission the knocking sound coming from the back side of my motor . What's causing that ???

Are you sure the torque converter was seated all the way back into the bell housing? Spinning it as you pushed it into the transmission?

Yes I locked it in place

Knock coming from the engine? Maybe loose torque converter bolts? Oil level... I don't know, just trying to jar your memory. An exhaust pipe knock...

It gets louder everytime I hit the gas pedal

Is it a engine knock, a rod knock, check the oil.

I don't no it's coming from backside of the motor