Hopefully someone a lot more savvy at all this can clarify a few things for me...

The pre '09 6.1 Hemis did not have EGR systems. To keep detonation down the cam has more overlap designed into it's profile. I don't know any of what I just stated to be factual, it's just what I've read...

The early 5.7 Hemis had EGRs on the 1500 series trucks, but not on the heavier trucks. How did the non-EGR 5.7 Hemi keep detonation at bay? The non-EGR 5.7s used the same camshaft as the EGR Hemis, thus the same overlap for both. Something in the computer's tune? I cannot find any answers anywhere...