Recently blew the engine in half on my 1999 3.8L series II

I have no real answer for you, but the same thing happened to my 2001 'Bird. I've had it 6 years, maintained it well: changed oil regularly, tune-up every year, etc. But last year, the engine blew up. My mechanic said it looked liked oil hadn't made it into the engine in a long time. Neither he nor I have any idea why or how. Nothing was wrong with the oil pump or filter. Hopefully someone with more knowledge as to the why/how this happens will answer your question.

My 2000 firebird 3.8 liter series 2 was making a ticking sound for a while, had trouble accelerating and it was leaking oil. Turns out it was the fuel pressure regulator and once I replaced it, it ran pretty beautifully and that ticking sound was gone.