In stock form the 5.7 has more power to weight. BUT money to power the 6.0 has a lot more for the cost.

either way you cant go wrong. The 6.0 is stronger (not that its a problem with cracking blocks) but the 6.0 can be made alot biger. if you have the cash the ls6 is more then enough power (405HP) for normal people out of the box.

 

Just reading some of the posts, some of you don't realize that the 5.7 is a direct swap for the 5.3/4.8. All of the accessories bolt up and the computer and harness work fine. I have yet to see a stock 6.0 without a power adder make as good of numbers as the 5.7. If you plan on going with a bigger cube motor the 6.0 is the cheapest way to go since you don't have to resleeve. If you are doing a head and cam swap, my choice would be the 5.7 over the 6.0. The aluminum motor also dissipates heat better. As far as the 5.3 heads being better than 5.7 heads, that is rediculous. The 5.3 ported heads with bigger valves are great heads, but they cost as much or more than any other heads with port work. Look at what JPR is doing with his heads, they are flowing 302 at 550 in lift. I haven't seen another head do that. Good luck on what ever you get!

 

Isn't one of the reason the 5.7's make more power is because of the higher compression ratio? If you put flat top pistons in a 6.0 to raise the compression to 10.5, would it make about the same or more power as an LS1 w/ the same mods?

 

The motor makes more power for several reasons. The compression is only 10:1 in the LS1, not much higher than the 6.0. Stock for stock the LS1 has more power out of the box, but if your are going to mod the motor it is a matter of prefrence.