How do I find out what ECM I have, cause I need to recalibrate my speedo and Idotn know what ECM # to enter in winaldl

 

The ECM is under the passenger side dash. Just remove the "kick panel", and you should be able to see it. You will need to remove a couple of screws. Then you can read the label on the ECM to tell you EXACTLY what the ECM# is.

But, you do realize that your particular vintage of F-body does not modify the ECM for a recalibration of the speedo. You need to do that in the tranny.