And here the cam specs of different F and Y bodies. Notice how the 98 and the 99 F-body have the same cam specs but completely different injectors offset.
The 97-98 injectors flow is 28.5 Lbs-Hr @ 4 bar The 99-00 injectors flow is 26.3 Lbs-Hr @ 4 bar
Is it possible that the injector design changed so much from 98 to 99 to request such a big change in the delay table?
Or did GM recognise an advantage firing the injectors a little sooner?