There are kits available.find a Grand West dealer.
I think you can browse the website but they wont sell to anybody off the street. At least last time i looked. Ima go look.
By the way, i also have a 76 dart sport.
The site bites. Cant browse anymore. Dont really want to become a dealer and compete with my regular parts supplier.
I guess if you contact them,they will give you contact info to your nearest supplier.