Razor is right. You just can't say I want power. You have to marry the whole system. If you want to keep the engine stock, and have a limited budget, and you are looking for good streetable power you cannot go wrong with the 2530. I am planning on these, unless I can get some GT-SS at a good price.
If you dont mind lag, a lot of guys are using T-78s, but that needs a lot of extra stuff to amke it work, meaning more money, more money