I have an '01 3/4 ton with a 24 valve enigine with an automatic transmission and then engine is just about trashed. I found an engine with 110,00 miles out of a truck with a manual transmission. Will it fit in mine without any modifications?

if you have everything from both trucks you'll be able to do it without having to buy anything else; depending on the year of the donor truck, of course. So long as its a 24v non HO it'll swap easy enough i'd say
TNutcher

It's an '02 nonhigh output engine and mine is nonhigh output too.

use your pcm and ecm and it should swap out fine. rebuild the old engine while its out

I don't know that it's possible. I had the tip of the # 2 injector break lose and get stuck somewhere. It still runs, but misses, idles terrible, smokes up a storm, mixed fuel and oil, and driving 20 miles blows all the oil out through the puke bottle tube. I haven't pulled the head to look into it, but I'm thinking the cylinder wall might be gouged. Is it still rebuildable?

do these motors have sleeves in them or are they like a conventional block?

no sleeves but reboring is not a problem cummins has all you need. fixin to rebuild one that has scoring

Really? I didn't know that it was still possible with a scratched cylinder. I think I'll hang on to the engine and look into rebuilding it.