Where do these belong..?

nodemon said
There were only 4 when I bought this manifold to tail pipe exhaust.. My first thought was they must be for the manifold to downpipe connection since there were only 4... I just used the 8 bolts and flat washers that came on the engine that came with the car. So, it's incorrect to use flat washers with the bolts..?

Actually, the location could vary depending on what manifolds you have, I just automatically thought of early 340 manifolds. They are held on by a combination of those washers with studs and nuts, or bolts, and some special "sleeved nuts".
Ebay image:

NEW 1968-70 Mopar 340 Exhaust Manifold Hardware Kit | eBay
Just an example-shop around for best price or a set for a different type manifold.