B&M Shift Improver Kit - GM TH2004R Transmissions BD DIESEL " 4 inch block - Most

4 inch block - Most common for level front/rear stance

meaning they stretch upon installation and must never be reused

No matter your head size or shape

When restoring your classic squarebody there is a good chance that the hood has some substantial rust or has the dreaded kink

Replaces GM OE Part Number: AC Delco 89060639

B&M Shift Improver Kit - GM TH2004R Transmissions BD DIESEL " 4 inch block - MostB&M Shift Improver Kit for 1981 1990 Chevrolet, Buick, Olds, Pontiac and GMC TH 200 4R transmissions, recalibrates your automatic transmission for optimum performance and extended life! Select the mode that best suits your application Provides crisp shifts on any stock automatic transmission Eliminates shift overlap and excess wear on clutches and bands due to slippage The B&M Shift Improver Kit the easiest way to get the stout performance you've