Proper fly wheel

[A1Avette79]

What is the proper fly wheel diameter and tooth count for a '79 with Hydramatic automatic transmission? Is there any advantage to aluminum vs steel?

[JohnZ]

What is the proper fly wheel diameter and tooth count for a '79 with Hydramatic automatic transmission? Is there any advantage to aluminum vs steel?

Automatics don't use a flywheel - they use a stamped steel flexplate the converter bolts to; your flexplate is 12-3/4" in diameter and has 153 teeth.

[A1Avette79]

Thanks John. I was confused - Ecklers shows a larger diameter and higher teeth count for my car but other sources were showing a 153 teeth count with the 12 3/4 diameter.