Big Block Truck Headers/Exhaust manifolds wanted

I recently removed a 400 B big block engine from a 1977 tradesman campervan to go into a 1977 dodge D-150.
It fits perfectly as far as mounts and pan go, but the passengers side manifold hits the frame rail; don't know about the drivers side yet as I had to remove the manifold to remove it from the van. any pictures or anything is a help