I'm guessing your talking about an auto, if so your better off doing a search on the TDR as most transmission thread end up locked as the posts heat up, this is by far the best and worse subject there is. My suggestion to you is to do your homework with the names posted and you decide as it's your money not ours, you will see people stand by there products and you will see the sales men coming in soon, bottom lines is there all better than stock!
Jim