I have just located a 1968 Cougar XR7G (Hertz), it is in my girlfriends mothers garage (she is 88) since 1989.

Hey - neat find! What's the story behind it? How'd it get there?

I am in the process of getting it running and at the same time trying to return it as much as possible to stock (kinda). It has a Holley double pumper on it now, looks like an 850. Does anybody have an idea of what the original Carb on this beast was, I am not happy about using one this big much less mechanical instead of vacuum.

The original carb was a 600cfm Holley with vacuum secondaries. I've attached a typical image of one, below.

The motor is the 390 as all G models were.

Yep - the good old '390GT'. For more info check out this detailed spec sheet, one of the many you'll find in our Obsolete Engines Textbook. 

As the work progresses, please be sure to keep us in mind for parts or literature. Our main business here at Fomoco.com is selling Genuine Ford stuff for classic cars. Best of luck with your new Cougar.