If you look on the log at 2:06 in, he goes full throttle and the timing starts dropping. Up through the 1-2 shift it pulls pretty good, but as soon as it shifts into second, the timing slopes down as the RPMs go up. It makes for a long acceleration through 2nd gear. I see the injectors getting over 90% duty cycle at 5200 RPM, but I don't think the injector duty cycle is linked to timing is it? I've looked through everything I could think of and can't find what is pulling the timing.
5.3 DBW Iron Block
Z06 cam
LS6 intake and injectors.