49 chevy 216 leaking antifreeze

I noticed yesterday that i have antifreeze leaking pretty good from the back end (bottom) of engine . I cant see where its coming from looks to be running out of the fly wheel cover . Engine is not overheating at all , checked antifreeze in radiatior (havent got to low) . Ran car all over this weekends with no problems , the only thing i have done lately was put a valve in the heater hose. That stopped it from being hot in the car itself while driving around , but i have noticed a sound that sounds like ithe pump is sucking ?. Its hard to explain a sound i know ! The valve is in the hose going to the thermostat housing (block) not the pump itself ! Is ther freeze plugs on the back end of a 216? thanks

 

yep

 

sure sounds like a freeze plug to me.

 

Yep , freeze plug behind the flywheel. Drop trans and chutch and pull bellhousing. Oh the fun!!