I'll tell you what, a 65mm TB is good, but not the best right off the bat. The SVT one is the best option. I have had a 65mm for about 1 1/2 months, and it has way too much throttle responce (compaired to the stock one) and takes a little getting use to. I had to buy and extra throttle spring to help me out. It gives pretty good increase in top end, but not an extreme amount, but the low end is increased pretty well.
Oh yea BTW, get ready to drop 2mpg in gas milage...I'm running 17.5
