Just so you don't think you are crazy, you have to remove the plastic splash pan to get a really good ook at it like the picture shows.
Oh, and I think it'* best that you just open the rad cap and disconnect the lower rad hose instead. Two reasons:
That petcock is just plastic and more than one person has broken it when it'* stuck shut from never having been moved/opened before. Plus it drains slowwwwwly....
And, if you have a lot of junk, chunks, and rust in there, it will only serve to clog up that measly petcok and maybe evenjam it open with a chunk.
Oh, and another thing. If there'* that much crap, including rust in there. consider the possibility that you may have leak problems once your done flushing it. Not trying to scare you or cry wolf, just warning of the possibility. It sounds as if the previous owner did not keep a proper 50/50 coolant/water mix in it.
Get it flushed, really well and replace with a good 50/50 mix. Your engine will thank you.
Mike: 1997 SE w/ 183K, aka White Horse
, Gutted Airbox w/K&N, drilled 180* t-stat, tint all around, clear corners w/SilverStars, "PONTIAC" light up tail, PEMs, NGK TR55s