HOW TO: Swap C4 Automatic for a Manual Transmission – Inline Update

By Modern Driveline • August 07, 2019 Posted in How-to's, Magazine Articles, Transmissions

Our six-cylinder Mustang build ditches the C4 automatic in favor of a five-speed manual

Mark Houlahan Tech Editor, Mustang Monthly

January 18, 2014

For those just tuning in, we looked over the shoulder as Brian Stilwell and his father-in-law Ricky Snelgrove hopped up the 200ci inline-six in Brian’s ’65 Mustang hardtop for our October 2013 issue. Brian’s update featured a bunch of Classic Inlines hardware, including their aluminum head and intake combo, a new cam with full roller rockers, and more. When the dust settled and the dyno came to a stop, Brian’s Mustang saw an improvement of 45 horsepower and 50 lb-ft of torque.