Modified Mustangs & FordsHow To Drivetrain
Automatic Overdrive Transmission Swap
An Overdrive Transmission in an Early Car Gives Balanced Performance for Acceleration as Well as Quiet and Economical Highway Performance
Step By StepView Photo Gallery
We've said it numerous times--nothing beats an overdrive transmission in an early car for balanced performance. Even with the lower rearend gears many of us run for acceleration, quiet and economical highway performance is possible. Keeping the pace with modern cars while also enjoying enhanced fuel economy, better high-speed performance, and quieter operation is easy. In a vintage Mustang, a T5 manual transmission or AOD automatic overdrive transmission is extremely worthwhile and a relatively easy swap. Few things top the feeling when you're out on the highway and the tach drops from three grand to two grand as the car quietly slips into Overdrive.
We have a good friend with a pale yellow 1965 coupe with an A-code 289 and C4 automatic. With a fresh engine rebuild, he wanted to maximize engine life and gain improved high-speed performance as well, so he decided to make the swap to an AOD. It’s gotten to the point where it’s nearly a bolt-in proposition thanks to parts offered by the EFI and overdrive conversion specialists at Windsor-Fox Performance Engineering. Trust us--it’s one of the greatest things you can do to enhance the driveability and fun factor in a vintage Mustang.