Good luck... I still haven't measured but, after looking at them this morning when I got in my truck to come to work, it looks like they're pretty different.

 

Not only is the diameter different (back are smaller), but the way they're mounted is different as well. The rear vents are not deep ... and they screw into the duct work within the flow-through console ... if I remember correctly. It's been awhile since I popped it open. For those who are scared to try, just push up on the padded armrest portion (while sitting in the back seat). You can then just pop the rear housing (with vents) down to see inside. Nice little hiding place back there.

 

Uhh (frustration mounting). Well I pulled the back apart (pulled on the vent and popped that interior piece open.

Well you're right on two things, it's a great hiding spot AND there is NO WAY to get the front vents to work on these back two.

Great ***** of fire, now I need to try and re-sell these things on ebay or here for what I bought them.

Any of you non-lariat/king ranch people check out the classifieds.

Duke