I almost bought the tti shorty ones for my duster, but had a set of 340 manifolds, so I just used the manifolds.
Cheap headers on a A-body I am not 20 no more, I am not dealing with the issues they have.
I remember my first duster, smashed flat on the drivers side.
I said "no more headers for me", and I had both Dusters on manifolds, with 2.5 duals out the back. 318 still has manifolds, but the 360 has Dougs. Only a good fitting header for me on A-bodies, or I'll stick to manifolds :)