What's the deal with this carb?

[myplague5]

Does anyone know anything about the holley carb I posted in this thread? There doesn't seem to be any info anywhere I've looked

http://fordsix.com/forum/viewtopic.php?p=374778#374778

 

[FalconSedanDelivery]

what is the List number ? its on the upper right corner of the airhorn , I have books that probably list its specs

 

[myplague5]

I've never dealt with carbs so I'm not sure what that is, I posted all the numbers I saw on there towards the bottom of the page... I know it was on my mom's 68 mustang with a 289 auto tranny, but I'm not sure if it was the original.