I'm considering buying a ZZP high flow throttle body as a future mod, but it does it really add the 7-12 hp that they claim?

http://www.zzperformance.com/products1.php?id=223

I doubt anyone has actually dynoed it but it is sopose to flow better than the larger L67 TB. In terms of performance, I haven't read anything but good reviews about it.

Oh, I just remembered, your 97 has a 4T60-e transmission right? If it does, you must tell ZZP that you need a throttlebody with 2 vacuum ports. Most L36 throttlebodies only have one since they come with the 4T65-e transmission.