Early Bronco 700R4 Automatic Transmission Swap

The Early Bronco 700R4 automatic transmission conversion is a proven upgrade for improved drivability and off-road performance. With a deep 3.06:1 first gear, the 700R4 is well-suited for rock crawling and low-speed control in 1966-77 Ford Bronco builds.

For best results, use 1987-92 700R4 cores, which include factory upgrades that fixed earlier lubrication issues. A “K” case from a GM 4x4 is preferred for added strength and durability.