1973-1987 GM K-Series 4WD Transmission Kits

Toughen your 1973-1987 Chevy or GMC Square Body 4x4 with our PerfectFit™ Overdrive Transmission Kits. We offer the most complete systems for your K-Series truck, featuring the heavy-duty TREMEC TR-4050 5-Speed Manual with its 6.16:1 crawler gear, and our A41X 4L60E-based 4-Speed Automatic. Engineered for a seamless fit, our kits provide modern highway driveability and rugged off-road performance. Each kit includes every necessary component, ensuring a straightforward installation with no fine print or hidden costs.