Good luck to you I have a 1973 454 4 speed I changed it over to fuel injection and electric headlight motors  did it myself I’m 84 years young

I put Vintage Air in my '76. I had to modify one of the hard vent connections to make them fit together. I called customer service twice with wiring questions and they were quick to help. I have a dozen pics or so of the install if you are interested. Cramming the flex tubes and wiring behind the gauge cluster was tough. 

I wasn't able to get the hard duct that goes across the steering column in place, so I just left the ducts open.  That worked fine.

I also wasn't able to get the ducts above the center gauge cluster in place.  It was just too tight in behind there.