1998 ignition timing question

[The_Bishop]

I have a question regarding the ignition timing table in my 1998 Camaro in regards to how it compares to the later model cars.

My car is modified from stock. I have deleted the EGR, installed an ls6 intake manifold, headers, etc. The long block is vintage 1998, with the 806 casting heads and 1998 camshaft, unmodified.

From what I've been able to find, the combustion chambers in the 806 heads are identical to the later 241 heads. The compression ratio is likewise the same. I know there is a difference in camshaft timing (1998-2000 is 202/210 int/exh @ .05" on a 116 LSA vs. 2001-2002 197/207 int/exh @ .05" on a 116 LSA) and they were equipped with the ls6 style intake, but this doesn't explain the rather vast timing table differences.

My question is should I be running the later style timing table? The high-load/high-rpm cells show 28 degrees in my stock tables, while the later model cars show 19 degrees. Surely the camshaft and intake change aren't totally accounting for the timing changes, or am I missing something else?