Motor is locked up... 5.3 or 6.0? What do I need?

[JasonZ10R]

I have a 2004 Tahoe Z71. It has 157K miles and it just blew up on me. Driving on the interstate about 70mph... all the sudden got a rough vibration from the engine. Instantly looked at guages... saw oil pressure at 0, Engine oil pressure low message and then before I could look back up the tach dropped. I pulled over and the truck had locked up but no fluids leaking. After a tow to the shop my mechanic told me that they tried turning the motor with a big breaker bar on the harmonic balancer and nothing. So they offered a used motor swap same LM7 with 112k miles and a 1 year parts and labor warranty. Second option was a new (reman I'm sure) motor with a 3 year unlimited mile warranty. I would prefer to do it myself to save money of course so what should I do? I have even thought about a 6.0 upgrade the LQ4 or LQ9? Can I use my current trans? What do I need? Any help would be appreciated!!!

 

[ezdaar]

Install a 6.0 as fast as you can.

Lq4 is low compression motor
Lq9 high compression motor. More power. Much better.