would a dual exhaust system fit?

Of course it will.

Search the threads, here's the summit system, which I run and love.


http://www.summitracing.com/parts/sum-680144/overview/year/1974/make/dodge/model/dart


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