Item Details



Part Number BM20260
Brand B&M
Part Type Automatic Transmission Valve Body Kits

Shift Improver Kit Suit GM TH400, 375 and M40, recalibrate your transmission

The B&M Shift Improver Kit the easiest way to get the stout performance you've always wanted out of your automatic transmission - and you get two modes of performance to select from: Heavy Duty, or Street/Strip. It's our least expensive and simplest to install kit. All you need are some hand tools! In the space of an afternoon, you can turn your transmission into a B&M-tuned unit! Ask the thousands of satisfied customers that have installed one in their transmissions!

  • Recalibrate your automatic transmission for optimum performance& extended life!
  • Select the mode that best suits your application:
    1. STAGE 1. HEAVY DUTY; Firm positive shifts without loss of driver comfort for improved performance in all street vehicles. Recommended for regular passenger vehicles.
    2. STAGE 2. STREET/STRIP; Provides positive shifts for high performance street use or for competitive events. This level is for the enthusiast who wants the hardest, quickest possible shift.
  • Provides crisp shifts on any stock automatic transmission
  • Eliminates shift overlap& excess wear on clutches& bands due to slippage
  • Application: Buick, Chevrolet, GMC, Olds, Pontiac - '65-'87 TH-400, 375 and M40




Product image(s) are for illustration purposes only. Actual product may vary.


For further information or questions please contact us.


  Delivery Info



Domestic Freight

All freight around Australia is handled by StarTrack Express.
Purchases under 5Kg are generally transported by Air and taken to the local post office if no one is home at the time of attempted delivery.
Parcels 5Kg and over are transported by road and are returned to the nearest StarTrack depot if no one is home at the time of attempted delivery.
If delivery is unsuccessful, a card will be left in the post box informing you of where your parcel can be collected.

Fluids & Parcels 5Kg and over will require a full address as road parcels can not be delivered to a PO Box.


No Instore Pick Up with eBay Orders

International Freight & Import Duties/Taxes

International freight charges will be shown on your invoice.
You may be subject to import duties and taxes charged by your government.
These are your responsibility and will need to be paid when you collect your goods.