B&M Shift Improver Kit Chev Turbo 350 Transmission # BM30262Shift Improver, Chevy, TH350, Each Filter Included: No Gaskets Included: Yes Full Manual: No Remanufactured: No Quantity: Sold as a kit. B&M Shift Improver Kits B&M Shift Improver kits are the easiest way to get the stout performance you've always wanted out of your automatic transmission. All you need are some hand tools and an afternoon, and you can turn your transmission into a B&M tuned unit. Each kit has two stages to fit your needs: RV Towing