I'm working on installing a Stillen CBE and have read that making sure exhaust isn't leaking is the main challenge. Will it be super obvious if exhaust is leaking? What are the signs of it leaking, just sound? Thanks in advance for the help!

 

Listening should be a good start. You can also put your hand around the flanges with the car running to see if you feel air coming out just DONT touch it may get hot.maybe stuff a small rag in muffler,not to where it completely plugs the exhaust put just to put some back pressure to check for air leaks .