What is needed in swapping out a 6.0 to a 5.3 in 2003 K 2500?

[indiansprings]

New to the site, my 6.0 in a 2003 k2500 just bit the dust, haven't got it apart yet but sounds like a horrible
rod knock/bent rod.
I can get a 5.3 with less than 7k miles for an insanely cheap price off a buddy, 500.00.

Before people raise hell about going backward in displacement, I really don't need the power of the 6.0 in my application for the truck, just need a good dependable powerplant. Would consider putting a performance
cam in the 5.3 to help it put out a little more.

Can I just drop in the 5.3 and use the cmptr and wiring harness I have off the 6.0? What would have to be
changed if anything?

[Chevy-Art]

You will probably need to get the PCM tuned. Especially going from 6.0 to 5.3, something fuel related. You can use everything from the 6.0.

[indiansprings]

Thank you for the response! Glad to hear it will swap. He had two 5.3 engines, I picked up the one with only 3000 miles, complete except for the coil packs, with the wiring harness included for 450.00 last night. The other one has 7000 miles but is missing the intake and coil packs, and wiring harness, I prolly should buy it for the 375.00 he's asking just to sit on the shelf.

What cam should I use for more low end torque? Should a person put in new springs and lifters as you would on an old small block.

Again thanks for the reply.