Hi everyone, new guy. Just blew up the LS6 in my 05, 148XXX miles, made a nice window in the block 
I am thinking about the LS3 upgrade, been doing a lot of research and here are the things, I found out, trying to just get the definitive answer on if I have the whole list or not. Seems pretty comprehensive, any thoughts?
Wrong crank trigger. Two solutions:
A: Go with the Lingenfelter 58 to 24x converter box. I don't know of the problems stated by jmilz28, but it's up to you if you want to go with option B.
B: Remove the crank and install the 24x crank trigger. Change the cam sensor to the 24x (black) sensor)
2. Cam/knock sensor differences
Tap the knock sensor holes to M10 and install LS6 knock sensors in them. Use KAT-4750 cam/knock adapter harness to move the knock sensors to the side of the block and connect the new cam sensor location in the front cover.
3. Wrong cam trigger
You need a 2x cam trigger so you'll need to use the 2005 LS2 sprocket (12576407). The problem with running this in an LS3 is that it's for a three bolt cam so you'll also need to change the camshaft. You can put in an aftermarket cam or pick up a low cost OEM take out such as an LS2 or LS6 cam.
4. Injector connector difference
You'll need KAT-A4758 injector adapters
5. MAP sensor difference
The LS6 uses a Delphi sensor and the LS3 uses Bosch. There are two solutions:
A. Run the Delphi sensor and use a small piece of hose to make up the difference in the grommet diameter. Fabricate a small metal hold down to secure the sensor. You will also need KAT-4751 MAP extension harness since the MAP sensor on the LS3 is located in the front.
B. Run the Bosch sensor and use the KAT-5185 MAP sensor adapter. You will also need to use the KAT-4751 MAP extension.
6. Throttle body difference
Use KAT-4752 throttle body adapter harness.
7. Need to use an 05 Vette fuel filter to get the pressure regulator as the LS3 doesnt have it on the rail.
Questions:
1) Can i use the LS6 headers, I think so.
2) What does everyone use to tune these?
I am planing on ordering this week since there is such a backlog everywhere (~1 month).
Thanks!
Norbert
I am thinking about the LS3 upgrade, been doing a lot of research and here are the things, I found out, trying to just get the definitive answer on if I have the whole list or not. Seems pretty comprehensive, any thoughts?
Wrong crank trigger. Two solutions:
A: Go with the Lingenfelter 58 to 24x converter box. I don't know of the problems stated by jmilz28, but it's up to you if you want to go with option B.
B: Remove the crank and install the 24x crank trigger. Change the cam sensor to the 24x (black) sensor)
2. Cam/knock sensor differences
Tap the knock sensor holes to M10 and install LS6 knock sensors in them. Use KAT-4750 cam/knock adapter harness to move the knock sensors to the side of the block and connect the new cam sensor location in the front cover.
3. Wrong cam trigger
You need a 2x cam trigger so you'll need to use the 2005 LS2 sprocket (12576407). The problem with running this in an LS3 is that it's for a three bolt cam so you'll also need to change the camshaft. You can put in an aftermarket cam or pick up a low cost OEM take out such as an LS2 or LS6 cam.
4. Injector connector difference
You'll need KAT-A4758 injector adapters
5. MAP sensor difference
The LS6 uses a Delphi sensor and the LS3 uses Bosch. There are two solutions:
A. Run the Delphi sensor and use a small piece of hose to make up the difference in the grommet diameter. Fabricate a small metal hold down to secure the sensor. You will also need KAT-4751 MAP extension harness since the MAP sensor on the LS3 is located in the front.
B. Run the Bosch sensor and use the KAT-5185 MAP sensor adapter. You will also need to use the KAT-4751 MAP extension.
6. Throttle body difference
Use KAT-4752 throttle body adapter harness.
7. Need to use an 05 Vette fuel filter to get the pressure regulator as the LS3 doesnt have it on the rail.
Questions:
1) Can i use the LS6 headers, I think so.
2) What does everyone use to tune these?
I am planing on ordering this week since there is such a backlog everywhere (~1 month).
Thanks!
Norbert