Did they change anythign significatly in the 4l60 from when it was hooked up to the vortec 350 to when they used it in the gmt800's behind the 4.8/5.3? Was there any changes internally that would greatly effect the drive terrain loss between the two? The vortec 350 put out I think 330ft lbs at 2800 rpms and I have a person who is trying to tell me that even though the 5.3 peaked about the same torque around 4600, it put more torque to the wheels across the entire rpm. I highly doubt that GM could change the internals of the 4l60 and the rear axle that much to make the newer gmt800's more efficient

 

doesn't sound like there is any reference to the tranny in the equation. I think he is just saying that the 5.3 has a flatter torque curve accross the entire rpm band over the vortec 350.

 

Internals are the same but the torque converters not(uses a different bolt pattern) but it should have the same drivetrain loss.

But I think what he is trying to say is that a 5.3L will have more overall torque from idle to 5500 rpms....not just peak.

 

He's using dynos of the rear wheels and saying that the 5.3 covers the 350 at all rpms and so on. The 5.3 has a broad torque curve, but its no where near as torquey down low. There is no doubt the 5.3 has a broader powerband. The 350 is dead by 4500