I've just recently picked up on a few comments that have led me to believe that there is a performance variance from year-to-year as a result of the LS1 heads. Is this true? If so, which year(s) have the best heads, and which the worse?

I know the 01s-02s benefit from the LS6 intake, but I had no clue that the heads were ever revised. If anyone would shed some light on this it would me much appreciated.

Thanks,
Josh

 

I think the 02's have the 241 casting that is said to be better than the other years.