LS4 Front-Drives 2005-2009 - Tap shift tranny?

I want to convert my non-tapshift Monte drive train over to tap shift.
I know I need the tranny and TCM, but the tranny that I found close is an 05 GXP SCV6. What are the differences between the 05 V6 and 06 V8 tap shift?
Can I just swap the valve body from the V6 over to the V8 tranny?
What are the gear ratios?

Thank you for the help, Rick

I was under the assumption that only the TCM is what controlled whether it had Tap or not. I just happen to have a GXP TCM sitting around that I'm not using. ;) The GXP has Tap, the Impala, Monte, and LaCrosse don't and I'm 99.9% sure they all have the same tranny.

Is the TCM from an LS4?
If so what would it take to get it off it's butt?

I was told that the tranny has changes to accommodate the trans braking and some changes in the valve body. But you know how rumors are. That is why I am doing a little "research"

Yep, $50 sound good? Someone else could give ya a better answer to the tranny question.

Actually I think it may be possible to tune the TCM for Tap, however I could be 100% wrong. Somebody with proper knowledge wanna chime in?

That might get a little complicated. I did hear the tap shift tranny is different too.

The LS4 transmission has even stronger parts and the belhousing is different in that it mounts the starter.