Engine Kits

1965-87 Turbo Hydro 400, 375, & M40 B&M Shift Improver Kit

1965-87 Turbo Hydro 400, 375, & M40 B&M Shift Improver Kit

Part #: 20260
List Price: $90.76
Our Price: $45.38
You Save: $45.38

B&M Shift Improver kit for the 65-87 Turbo-Hydro 400, 375, and M40 3-Speed automatic transmissions.

The B&M Shift Improver Kit is 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 B&M's least expensive and simplest to install kit. All you need are a few dollars and some hand tools! In the space of an afternoon, you can turn your transmission into a B&M-tuned unit! Just ask the thousands of satisified customers that have installed one in their transmissions!

Stage 1 - Heavy Duty
Firm positive shifts without loss of driver comfort for improved performance in all street vehicles. Recommended for regular passenger vehicles.

Stage 2 - Street/Strip
Provides very positive shifts for high performance street use or for competitive events. This model is for the enthusiast who wants the hardest, quickest possible shift.

  • Provides crisp shifts on any stock automatic transmissions.
  • Elimination of soft sluggish shifts, shift overlap, and excess wear on clutches and bands due to slippage.
  • Improves transmission life.
  • Transmission removal not required.


Chevrolet, GMC, Pontiac, Olds, and Buick


Brand B&M
Filter Included No
Full Manual No
Gaskets Included Yes
Notes Does not fit transmissions built after 1987.
Part Type Automatic Transmission Shift Kits
Product Line B&M Shift Improver Kits
Quantity Sold as a kit.