Bought used cobra manifold, how to clean?

I use Gunk Engine-Brite....the spray foam, and it cleans em sweet...wont hurt the paint either...for the inside, spray it down good and let it set 10 mins or so, then hose it out real good...
 
I hope it will love it even more when i switch to 9#'s in a few weeks :D .

I guess im gonna go start making an intake and simple green stew.

On a side note, im going to get a new TB as well. What size should i go with once i switch to 9#s and 36# injectors?