Exhaust for a 1973 Duster 340 (Pics Included)

The other question not asked so far is what do you want to do with the car?
If you will be taking it to the dragstrip, and want to go quicker, headers are a big help.
But you can still goquick and have lots of enjoyment with the exhaust manifolds - along with saving money and all around easier to deal with.
I'd say if you're not sure, just have a shop put a set of dual pipes on. When you look at the car, look to see if it has both exhaust hanger brackes in front of the axle.