Ticking sound

Hey guys, I have this ticking sound coming from the back of the motor around the BellHouse. Its always there whether I rev up the engine or just let it idle....If the motor is running I can actually feel it in the bellhousing/tranny area if I put my hand on it...I have been told it might be a cracked flex plate? Does this sound like it makes sense?
Its just a Mild 318 with a 904 behind it....
Thanks
Brad