Rear Lowering Springs on 07 Shelby GT

Can anyone confirm for sure what model rear lowering springs came stock on
the 07 Shelby GT

Numerous web sites are so mixed and parts suppliers between the M 5300 P code 1.0"
or the M5300 K code 1.5"

It seems there should be a stamping on the Spring but, unable to find one yet with limited view.

 

Just in case anyone else would like to know.

Was able to find the stamping, it is a K code 1.5" both front and rear