While researching my 96 2 door a while back, I learned that ofcourse 96 was the first year of the Vortec. Cool. After further research, I see a 5 HP difference between 96 and 97+. Now, from what I've read, the "sawteeth" casting on the end of the heads is a sure sign of Vortec heads. Yeah, mind don't have these. Casting numbers come back as Vortec though. Did they revise the head design between 96 and 97? Is that what accounts for the 5 HP bump? Or was it something else, like a different cam? I can't seem to find a good breakdown of all the engine specs/parts. To further complicate things, I just did a search to show the 5 HP difference I am talking about. According to Wikipedia, the Vortec was first used in 95! Ok, so was it a mid-year change? Secondly, it shows the HP to be 255 HP from 95-99. Now, MotorTrend confirms the 5 HP difference between 1996 and 1997. I'd really like some more info on this!