Just got done replacing the gears in my 96gt with limited slip. I have normal diff fluid in their now, but have heard a few people say that I should use a special kind because of the limited slip. I know there are a lot of products out there that are saposed to give you car an extra 50hp simply by adding fuel additive, and I don't want to spend a bunch of money on a gimick like that. so any advice would be great, thanks.