The reasons and why are not set in stone it varies everyday on warranty replacing major parts like engine, transmission, rear end or expensive parts. 5.0 you have to be sure there's no problem would be take engine apart. Think about this what that guy says it's a tick could totally different noise. I've been there before chasing a noise that wasn't there it was something else.
Ghost In The Machinery.
2012 Shelby American Mustang GTS 580rwhp 485 ft/lbs Grabber Blue White Stripes
Ford Whipple, 5.0L, Tremec XL Magnum, MGW, Centerforce DYAD clutch, Boss 302 Torsen w/4:10s, 302R EPAS, Eibach Coil Overs, Fays 2 Watts Link, Dynotech DS, Shelby UCAs/LCAs, Wilwood brakes 6 piston 4 piston, Drake Bump Steer, heavy duty cooling, welded axle tubes, Interior Package, GT4 wheels, Borla Touring axlebacks, GT500 rear valence w/parking sensors, and airbag cover signed by Carroll Shelby.