Poly 318

[Kevin H]

Dodge Dart, Plymouth Fury, Belvedere/Mayfair all from circa 1955-60, possibly a bit later, particularly in Canada.

Although some models of these cars used the 313/318 engine, the outlet from the manifold exited at the centre or rear depending on body type. Not sure whether the length of the outlet also may have varied.

Here's a lengthy discussion on the topic!

http://www.bristolcars.info/forums/8...-manifold.html

One of the manifolds on the Bristol incorporates a heat control valve. I think it is the left hand one, but it depends on which way you are looking at the car!