The automatic transmission flexplate in your Mustang serves a few different purposes. It acts as an external crankshaft balancing counterweight, a driven starter gear, & as a mounting flange for the transmission torque converter. Make sure you have the best one for your 4.6L or 5.0L Mustang & the flexplate bolts to go with it!
Testimonial: Coyote swap parts a step above the rest.
Late Model has made choosing the right parts for my coyote swap fox body much easier. With a dedicated section for this type of build and constantly updated with the latest parts it was a clear choice for me. They even did they're own swap with instructional videos. Thanks Late model!