Oh wow, youre right. Heres the table from a stock 2004 5.3

 

you guys think i don't know this?? that's why i said "when its cool out". my timing table goes from 21 up to 23 before shift. as it warms up my timing comes down. my 12.33 run iat's were 95* with 18.5* of timing. about the bottom of 2nd gear my iat's dropped to 81* and 22* of timing. from there the temps slowly rose and the timing slowly went down to 90* and 18.5* of timing. now on the street on a 70* day on a steady cruise (cruising iat's are 1-2*over ambient) i can smash it and it runs full timing. and oh man it is nuts. nothing like the front tires breaking loose on a 40 punch and almost loosing the wheel.