Thanks for all the advice/suggestions.
I ran synthetic at the last oil change for about 1000 miles. It seemed to be getting really dirty so I changed it again. I used 10w30 instead of the recommended 5w30. It didn't make any difference but it has 3000 miles since then and still looks pretty clean.
I didn't get it on a rack but I listened to it with a stethoscope and the noise seems to be coming from the right side at the base of the head. I guess it could be piston slap but it's hard to tell without tearing into it.
The engine runs strong and doesn't smoke or have any other problems but I don't want to lose my core if I do get a reman.

 

I've had reman'd ATK engines. I had no complaints, got good service out of them. YMMV. Jasper is another engine remanufacturer, gotten good reports. When I was looking for a replacement engine for my 96, I was looking closely at Marshall.

If you get a re-manufactured engine, you will be pulling everything off to get it down to a long block. The standards, from my experience have been that the engine must be free turning & rebuild-able--no seized blocks. You probably could pull the heads off for a look and not disqualify the long block from reman. Ask the remanufacturer about this.

I'm kinda of mixed feelings about switching over to a 5.9 or 5.2. They ARE great engines--world beaters, even, reliable and long lasting. But it really is a can of worms--basically, you're going to replace all of the drive components between the front and rear differentials. A lot of work/figuring/adapting/fiddling. Might be economically feasable, but worth all the extra time?

Alternatives, find a decent low mileage 4.7. Or buy a beater something to drive while you rebuild your present engine. Our friends at Chrysler had some engineering & quality issued in the years before the bankruptcy. The old "New Chrysler" died because they were building lousy stuff. Is the 4.7 an inherently bad engine? I don't know, but 120,000 miles on the clock isn't very good.

So getting a remanufactured engine might be a good solution--but any engine you don't have the opportunity to manage the rebuild is a crap-shoot, in my opinion.

 

http://www.powertrainproducts.net/mo...oductCode=1296

I understand what you are saying completely. When I bought this truck the main reason I chose this one is because I had all the service records etc. It seemed to be taken care of pretty well but ya never know. You can get a bad one in anything.
The truck is well worth the money both from a resale and personal standpoint.
I've done several rebuilds over the years and several long block replacements. I admit it hasn't been on a Dodge and not on anything as new as 2003 but I am pretty sure I can do it.
I have access to a lift and a pit if I need it.

 

It seems that a 4.7 either dies early or goes forever and ever. I have seen the go out with low 100k's and have seen some with 230k + still going strong.

 

It just kills me that it doesn't smoke at all. It has great oil pressure and runs very strong. The engine is clean inside and I love the truck. But now it has a knock. I might try to get a short video this weekend but it really seems to me like a crank or rod bearing.

 

may sound kinda crazy but i developed a warped manifold that resulted in an exhaust leak at start up then got progressively worse, drove me nuts trying to pin it down

 

I think I'd pull it out, tear it down and look for what's ailing it. My guess, from what you say, is a rod knock. If you can fix it, you can salvage the engine without a rebuild--& save a coupla grand in the process. Money that you save is tax-free, interest free income.

It's funny about modern engines, they can go almost forever. My 96 5.2 is my daily driver and has 235k on the meter. Oil pressure is good, no funny noises except for the pinging that old engines get, and after an almost complete change of gaskets and seals, it uses almost no oil. I have a spare, but I'm waiting for the engine to go slightly fubar before I spend the time changing it.

 

I may be crazy but I'm thinking its something other than the engine get it to a very good shop and get an opinion or two or three.

 

What do you have for oil pressure, use a mechanical gauge, when it's making this noise?

 

UPDATE AND GREAT NEWS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!

Yesterday I took the truck to my Dads house because he has a 4 post lift and a pit. This was going to be the "figure out exactly what the noise is and make a decision" analysis.
On the way I heard a sharp bang followed by a lot of noise so I pulled over immediately.
The belt tensioner completely let go. The center part where the spring is came completely out and allowed the pulleys to go into the radiator. So after a new radiator and some hoses and a new tensioner I started it back up today expecting it to sound the same...wait for it....completely quiet. No knocking no nothing.
Apparently all the noise was the tensioner.
I don't understand it but the knock was a steady noise with the engine--no interruptions--a steady knock knock knock knock. I could hear the noise most prominently when listening with a stethoscope at the front of the head. But not really at the tensioner which I did check out.
300 is much better than 3000 so I am actually a pretty happy camper right now.
I would have been really pissed if I had replaced the engine only to STILL have the noise.
Thanks to everyone for all their help and advice.