I am stumped on this problem,i picked up this 68 RR a couple of weeks ago and drove it home about 150 miles on back roads running anywhere from 35 MPH to 65 MPH and had no problems in the engine.

However i developed a sound in the motor area that sounded exactly like a Fan belt squeal or alt bearing squeal and changed Alt with one from NAPA and also changed belts..still there after the change!

So next thing i thought Water Pump,Changed that and still squeals..

So i was stumped again and thought OK lets try it w/o any belts on P/S and Alt...Still squeals..

Now Finally i am done for a few days with it,so i put in a OIl Prssure Gauge to Keep an eye on Pressure and on start up it is almost at 80LBS and as u can see in Video Here starts up fine and no squeal.
I was using the old hose trick to find any small unheard squeals in engine compartment.This is a Cold start from overnight sitting.
http://s1260.photobucket.com/albums/ii566/twinscrew698/?action=view&current=IMG_2129.mp4
Sorry about the video Quality and whistling sound as i was working by myself and trying to get the IPHONE to sit up by itself.
Then as u can see after a few minute warmup it started to squeal in this video.
http://s1260.photobucket.com/albums/ii566/twinscrew698/?action=view&current=IMG_2130.mp4

Then after about ten minutes in this video.
http://s1260.photobucket.com/albums/ii566/twinscrew698/?action=view&current=IMG_2131.mp4

I have been told a few things that could cause this but figured i would see if any one else has had this happen to them!
Any help would be helpful to me if you can!
Thanks

I know you changed the WP but take its' belt off (1 minute max) just long enough to see if that's it. Might be an issue with the round oil slinger down on the crank snout. Any possibility it's coming from the rear (torque converter) area?

as said above, my first thought was oil slinger put on backwards.

Is that a belt rub mark I see on the water pump pulley snout?

Do you have a fan clutch on it? Could be on the way out. Sounds like mine did just before the fan went through the radiator.

RapidRobert:
I did take belts off completly and let it run for about a min!No Belts at all!
Am gonna Check Converter Next when i have someone here to help.
Dodgem:
Done all of that!
JohnRR:
Correct no belts at all!!
65rbdodge:
Gonna have to look at that!
Stumpy:
Noise still with belts off.
R/T1968R/T:
Yes it does have a fan clutch on it,That was another thought but run the engine w/o Belts hooked up so clutch was not turning.
Gonna check on T/C when i get some help to put it up on ramps and start it!
Then maybe go into the oil slinger after the weekend!
Thanks for he input all,if any one else chimes in it is something i can check out later..

too much timing will also make your water pump squeal like a pig when you rev. i have no clue why but mine does that. back the timing down and it goes away!

Had this similar problem on my friends 68 Roadrunner after we broke in the 383. We were hearing a loud squeeling at the front of the engine. Well it turned out that the the new bolts that were used to
mount the pulley on the crankshaft, were too long causing the bolts to scrape against the timing case cover. We put in the correct length bolts and no more squeeling.
This may or may not be causing your problem, but it's something to check.

I had the same problem on 440 in a 71 Challenger the bolts were just a thread to long and once it warmed up they touched the cover just enough to make a very loud squeal. Shorter bolts is all it took.

Going to check those bolts out as well,as he had really long bolts on the fan clutch that was on it so it is a good chance he done the same!
Something else to look at when i take it apart!
Thanks GMP440 and 2002blurt...

it not the bolts since it still making the same noise when the belts are off! I'm want to go with the oil slinger.

check the timing cover, to see if it's bowed out ,and toouching the balencer. I had this happen,and changed a waterpump for no reason.

Are u capable of removing the distributor. You might have a top bearing going or gone. Just a thought though .

Ok now that i am back in town,i will be tearing this down in the next few days and taking all of your suggestions!
Has had my family members stumped too as i showed them the video that i took with my phone so we will see!
Took it apart as you can see the oil slinger was hitting the timing cover as it had a little bit of play to it so it was moving around a bit also!

Also i dont know if it was the wrong one but i had one still in a 440 i had laying around and here is the difference!
The one i took out that is on the left and the old one i had on the right!