How much noise does an oil pump make when it falls apart?

[gordyzx9r]

1970 Chevrolet C10 CE10934
Motor: 350 CU. IN. V-8 ENG
Transmission: 4 SPD TRANSMISSION
Differential: POSITRAC AXLE

So, I drove the truck quite a bit the day prior. Go to start this morning and:

1. Sluggish start, almost struggled to turn over as if the battery was dead (it's not).
2. Once it started, it ran on it's own but it sounds like someone threw some nuts and bolts along with a wrench or two into a washer or dryer.
3. I can feel this clanging through the pedals and the floor boards.

I've had rockers fail before on other cars, and I've had pistons go, but none of them sounded this loud or made a clanging noise as if something was rotating around and beating against something else.

We took the valve covers off and all the rockers look good, valve springs, push-rods look good...nothing is broken, bent or seems out of place.

With the valve covers off we started the truck and everything appears normal. The sound was not coming from that area. However, shouldn't oil have been spewing or spitting out while it was running?

I had just changed the oil the about three days ago and there were no particles of any kind, even cut the filter open. Checked the oil and the oil on the dipstick seemed fine...we'll drain it in a couple of days and check again though.

Keep in mind the truck seems to run fine (for the minute we let it run trying to figure out where the sound was coming from), but something is clanging around in there and it sounds/feels like it's coming from the pan so we're going to try to remove the pan without removing the motor and I found these threads:

http://67-72chevytrucks.com/vboard/s...d.php?t=354119
http://67-72chevytrucks.com/vboard/s...d.php?t=539127

Ideas on what it may be or what it isn't?

Edit: It didn't appear the starter or fly wheel ate itself.

[mongocanfly]

You say you got oil..what about oil pressure? Youre right that you should have oil coming thru the pushrods and oiling the rockers..I've had em pushing so much oil thru them I had to put rags over the rockers to keep oil in.. got a 4spd..have you pulled the dust cover off the and inspected the clutch?.. if my oil pump fell apart most of the noise would be me cussing up a blue streak..haha..you could have a rod cap loose..I had that happen before.