I'm on my (in my F-body)second Opti, well it's going out too so I'm considering an LS swap in lieu of replacing it for the third time. and as Greg said have a 97 (LT1)F body and 99(LS1)F body, and there is no contest the LT1 is fast but the LS1 will smoke it. I think the thread was what was the best swap and most of the post said that the LT1 makes power and it does, but long term the LS1 is the way to go.