I have a 73 scamp 318 stock ps, pb, and going to convert to dual exhaust. it seems I need 340 exhaust manifolds I think .I am not looking to be original but loos like a tight fit. Thanks in advance for your insight.
340 manifolds will fit your car with no problem. 340 manifolds were used in 73 A bodies from the factory (340 engine). But you didn't say if you were looking for the early 340 manifolds of the later ones, there is a price difference.