Some trucks have more timing that others from the factory. Personnally, I think it was due to the tolerance in how the factory mounted the tone ring on the backside of the cam gear. Also due to variations in the pumps as well.
I know that everyones combonation is different but for mine, I was using a hotrod pump, drag comp, big injectors, and smarty on #4. It had plenty of timing, if the temp dropped much I would pull out some more timing by fooling the IAT sensor.
When I dyno'd at Floor-It, Marco himself was there. Out of curiousity on a couple runs with the smarty only on #9, he then tweaked the smarty to add more timing that normal and we saw power drop. Kind of confirmed that for my truck, in that setup, I had all the timing I could benefit from...