Coolant Leak on back side of motor on 2001 5.4 Need a little help

[03Cobra]

Should have a camera to snake behind there soon but I had the intake replaced because of a coolant leak from the cross over that was filling the valley. Now that is fixed but after that was done there is a leak from the back side of the motor somewhere doesnt look like its coming from the new intake where else could I look it kind of looks like its on the driver side it started as soon as I got the new intake on I noticed a smell a day or two later and noticed the coolant tank was a little low so over the past 2 weeks I have been adding a little fluid to it each day now its leaking pretty good and its only really doing it when the motor is running. I have put 2 gallons in it over the past 2 plus weeks seems the leak has gotten slowly worse. Where is the freeze plugs on the back of the motor and does the back of the heads have them as well or just the block?