Gen 3 5.3 timing vs gen 4 5.3 timing

[Gregs]

I was bored this afternoon and I started thinking about the benefits of using a timing table from a gen 4 5.3 on a gen 3 5.3. I looked at the two tunes and it looks like the gen 4 tune has more spark advance than the gen 3. Am I completely overlooking something here? I know the airflow between the engines would be completely different but i just can think of any reason that the timing should be different. what do you guys think?

[joecar]

Post the two .tun files you were looking at... maybe there are airflow differences.

[Gregs]

oh i'm sure they have somewhat different airflow values, as the get 4 has a virtual ve table, but the gen4 intake manifold appears to be the same. i'm sure they played with something in there to make room for the afm. the gen 4 tune is only like 2-3* more, i was just wondering if maybe gm had revised its opinion on desired spark advance.