[Richard Coutts-Smith]

"Rich I think it is because supporting the heat shield from the two manifolds meant there had to be two different components, a forward one & a rear one.

Supporting the heat shield independently meant one manifold could be used in either position. Another factor might have been the difficulty of removing the retaining stud if it had become too encrusted with the effects of heat, rust & time."

Sounds logical to me Clive, but I notice that the engine with the cast Heat Shield mounts is later than the one without (11347). How was the shield mounted without the manifold casting? I do not have one on the Humber, and I assume that the one pictured is bent, and should be flat.
Rich.