B&M's Transpak is a shift kit in a box! This kit allows you to increase your shift firmness for a better feel and a longer lasting transmission. Includes shift kit, filter, and gaskets. This can be done at home with ordinary hand tools, and includes B&M's tech line should you run into any questions.
For GM TH400 transmissions
NOTE : This is not a repair for a transmission with a shifting problem. This kit is intended to be installed in transmissions that are in functioning condition. If you have a transmission that is not shifting properly, you should see a qualified transmission servicer and have it inspected prior to installing this kit.