We need more feedback from the people making thousands of views of this archive.
At present, the exhaust exit from the engine bay is seen to be at the rear until approximately body number 60 – i.e. all aluminium cars. Here is a good rear exit detail through the lower flitch panel (with a later front exit exhaust currently fitted). The construction of this panel is steel overlayed with aluminium.
After this time, the exit moved to the front of the same panel, enabling the exhaust to be routed outside the body and presumably keep heat down in the engine bay. This 250000s car shows the original removable plate which allows easier disassembly. These panels are double layered steel.
There has recently been evidence presented of an early steel car – its body number is present – which has a REAR exit and no evidence of an original front hole, as would be expected from a later body. Could this be a body which was made in the factory early on in steel as a test at the same time as the early 65s – and not numbered until the steel cars were introduced?
Your photos of exhaust details emailed to the archive would be appreciated, if they show things which can extend the information this thread should contain, and especially if they better pinpoint the design changeover point.