99 concord 2.7 leak, experts needed

I found this concord, graged.
my grandpa said it was leaking water,
i fiddled with it and check all the hoses i could see.
changed the thermatstat and seal.

there is a little non threaded hole, looks to be made from the factory, next to the thermastat housing. water pours from it.
i called a chrisler tech, he said it was a heater by-pass and i could plug it up at the risk of loosing the heater. so i did, it sealed.

now it looks to be leaking from where the bell housing of the traney bolts to the block, i pulled the dust cover( i think) the piece that corner shaped with 7 or 8 bolts the bolt on the bottom side of the tranney and the block. i can see the lower side of the fly wheel.

water pors at a rapid pace, looks like two streams come down 3 inches of center looking at the fly wheel from the front. anything 3 inches or higher on the tranney and block are clean/dry.

chrisler said there might be a freeze plug on the back/in there thats bad.

i dont know what a freeze plug is, does the motor have to be pulled, would pulling the tranney be easier to get to the back of the block

i have some good experience working on cars, but im not sure what to do.

Update:

looked in a autobook today. i saw the hole that i pluged by the thermastat housing is called a water pump weep hole. it leaks when the water pump is bad.

anyone have this happen?

so i plan to change the water pump, good/bad idea? advise/tip?

any adive from anyone would be helpful:crying: