3" outlet with a 6" inlet so a filter can be clamped on it.

Any thoughts?

Hmmmm.... so you'd be clamping it to the outside of the throttle body? Would attaching a filter negate the effects of the stack? It might end up being the same as a regular intake pipe.

The velocity stack would go on the end of a CAI pipe. In my case it would go on the end of my intake pipe that goes through the charcoal canister hole into the bumper.

But you'd have the filter on the end of the stack, right? I wonder if it would affect the stack'* effects. By the way, what kind of gains would you hope to see from the velocity stack? What are they proven to do? I'm not all that familiar with the concept, and I'm too lazy to Google it right now

Sure I'd have a filter clamped on the end. I don't think it would effect the gains by much. What kind of gains? not much. Somewhere in the 5 whp range with no ill effects or trade offs.
I'd like to stay away from the fact that dynos can be withing +-5whp and that 5whp is not worth it to some people.
Once I get my trans situated, I would like to SQUEEZE as much hp out of my current setup and every little bit helps.
Anyone else familair with the concept and think it would work?

You would need a filter with a 6" flange then, wouldn't you? Or am I visualizing this incorrectly? K&N does make filters that big, by the way.

Yep.
It would look something like this:

If you do a search, IIRC, there has been mention that this creates turbulance. :?:

Couldn't find what your talking about and I don't see how it could.

Seems awefully similar to a TB spacer to me... I have to question how effective it would be all the way up int he fender well.