Upgrade the 4L60E or replace?

[CoryM]

650 rear wheel? I say it makes more sense to start with a 4L80E.

Thats what I was saying. But after looking around there are a couple kits that claim to handle 650+hp so I think thats what he is going for.
http://www.ckperformance.com/
www.4l60-e.com (raptor trans)

Thanks guys.