Headers will make the engine breath better, even the cheap ones.
I put headers on my first duster, my ex-wife drove it for a daily driver for years, never again on a a-body.
Complete pain in the butt, they were blackjacks, typical cheap headers, beat to fit in place.
Remove to change starter etc, after a few years the drivers side was almost smashed flat from hitting on the road.
When I built my current duster, I used stock 340 manifolds, easy, done.
FYI summits pre-bent header back exhaust fits good if you take your time and trim a few pipes, I used Accurate down pipes to connect to them, all installed on jack stands in my garage.
