I've been trying to be nicer on here but yeah... you would know 100% for sure if a rock got into your motor. I've seen hydrolock before but NEVER a rock in a motor. I've also seen what happens when some idiot just slaps a motor together without checking tolerances or taping the intake ports and dropping something in there and not realizing it... does not run long or at all... OR it runs fine and you never know because the guy got lucky with the tolerances or the piece that got dropped in just went into the crankcase and stayed there for the duration.
2000 Mustang GT Steeda #0048
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.