Anybody here swapped an LS motor in a 96-98 C1500???

I own a 97 C1500 with a 5.7, the truck has 197000 miles on it and still runs like a champ. I put a new trans in it 5000 miles ago. The 5.7 just started using oil, only a quart between oil changes and I was debating rebuilding it or possibly getting a crate motor before it starts getting tired. The reason I'm asking about an LS swap is because I have a 5.3 that came out of a rolled 2001 Tahoe with only 20000 miles on it. I have the harness and the computer as well. Was just curious and any info would be greatly appreciated.

Brian
http://a5.sphotos.ak.fbcdn.net/hphotos-ak-snc1/7017_1237101252122_1366961239_686083_1427439_n.jpg

the transmission is different . the pcm controls of the new engine will not work with the 1997 tranny.

using a quart between oil changes is normal with a 200,000 mi vehicle. especially if this has used dino oil over the many years.

how many miles on a oil change ?