I have oil pressure, now not sure I never did, oil light never came on the first time I fired her up so I'm assuming it was ok (didn't see the absence of the oil light) 
but there's a nasty knock and gets real bad when the throttle is opened.
Sounds like it's a rod. Hopefully it's not spun, but to me, it sounds pretty bad. Based anyone's experience with these motors, does a spun bearing sound worse than say just a bad rod bearing?
Too bad, as it runs really well except for that. I guess the next step is to drop the pan and take a look.
but there's a nasty knock and gets real bad when the throttle is opened. Sounds like it's a rod. Hopefully it's not spun, but to me, it sounds pretty bad. Based anyone's experience with these motors, does a spun bearing sound worse than say just a bad rod bearing?
Too bad, as it runs really well except for that. I guess the next step is to drop the pan and take a look.