I don't think you'll get any power gains. Jus better throttle response.
I'm sure someone here has done the TB porting and then bought the 65mm TB.
They will be the best to answer your question for both TB's and their effects.
well first you have to get the throttle off the mani..
ok looking into it, youll see that the whole doesnt match the vavle thing. the whole is like an oval. the vavle is a cirlce.. youll want to dremmel out the rest of the side to make it fit the throttle vavle. but first make sure you put eproxy on the out side of that wall.. make it about a 1/2" thick.. then let it dry for about 12-24 hours.. if you have the fast drying stuff.. takes about 2 hours. start to dremmel out that side of the circle to make it a complete circle. youll notice that youll dremmel down to the eproxy.. thats fine.. thats what its there for.. now you have a ported throttle body!