I run the exact same system on my 74 Swinger but bought it from Jegs.
Jegs and Summitt brand exhaust is made by the same company which is Pypes if i remember correctly.
The system sounds great
A vid of a car running the system is linked here:
http://www.forabodiesonly.com/mopar/showpost.php?p=1970230368&postcount=47