As far as I can tell, the only difference between the LS1 and the LS6 is the 243 vs 241 heads (2cc smaller chambers and sodium filled valves) and the camshaft. Is there anything other difference between the 2 engines that I don't know about?

 

I'm pretty sure the LS6 block has its own casting. I don't know what's different between the two blocks though.

 

LS6 also has stronger main bearing bulkheads.

 

All 2002 up LS1 engines use the 12561168 LS6 block, other differences are the 243 heads, LS6 camshaft, and the coated pistons (skirt & combustion surface)

12561168 Engine block has holes cast into the bulkheads to improve bay to bay breathing, the previous 5.7 blocks had the holes machined after the block was cast. Also 12561168 blocks have threaded holes for a timing chain damper, I was suprised when I took the timing cover off my crate engine and saw a timing damper.

 

Intake manifold is different too.

 

And hollow valves on the LS6

 

Some 2001 LS1's actually came with LS6 blocks. I know, because I have one. Lol

 

Weiner also 6 heads have the sodium filled exhaust valves

 

I would assume we all would know that about the LS6

 

Yah I am a genius, don't *** with me