Didn't touch the bearings, but when I turned the crank over by hand it didn't make a sound, now when I turn it by hand I can hear it. I heard it instantly when I started the motor

 

What exactly did you do to the engine? When you say you "Rebuilt it" Did you actually pull it out of the truck, Or just pull the heads and do what you could with it in the truck?

 

Yeah because when i say rebuild I mean completely broken down, cleaned, machined and reassembled with new parts. If you are spinning the crank by hand and hearing it and even more when the engine is running then STOP NOW while you are ahead and at least check the oil for metal particles and drop the oil pan to inspect.

 

I pulled the motor, stripped it down to a short block. (crank, cam left in) Replaced one connecting rod that broke, had the block inspected. Turned over fine with no noise.
Today I noticed that it changes pitch when I put the brakes on, whether its in park, D, etc. What could that be?

 

Starting to sound more like an alternater issue. Not certain, but you do change the electrical draw a little when you put the brakes on, due to the additional lights that are lit. Try turning on the lights and listen to what happens.

 

The reason the motor was rebuilt was hydrolock. Could a bit of water spray fry the alternator?

 

Fried maybe the wrong term, how about the bearings are shot. The alternater should not be hard to turn. Like I said before, if you think it is the problem then either listen to it using a stethoscope or remove the belt and start the engine and see if the noise is still there. You will probably catch flak for not doing a complete job on the bottom. Hopefully the small amount of effort/$$ you saved won't come back to bite you. Good luck..

 

If I screwed up and put one of the rods on backwards could that be it? Had them all labeled with # and direction but who knows

 

The pistons are marked on the piston pin bore
surface with an raised “F” or arrow on top of piston
indicating installation position. This mark must be
pointing toward the front of engine on both cylinder
banks. The connecting rod oil slinger slot faces the

front of the engine.
Assuming you took note of these indicators when installing the piston/rod you should know if everyting was assembled correctly. But since you asked, I'm thinking perhaps you didn't. Good luck.

 

Yep I did check with those markings.
But I did just remember, the torque converter got dropped on the concrete. Could this wreck the torque converter? Newbie questions I know... did a lot of research but apparently not enough
Popped off the belt and the noise is still there. For some reason the alternator spins freely now?