800 ° C at 3000 rpm

Does the rear cylinder run hotter or colder than the front cylinder?

I would doubt there would be much, if any difference because in the Morgan configuration there is no front/rear. on a motorcycle it would make a difference

Driver side (USA) front cylinder as labeled by S&S.


Rear cylinder or passenger side.


Looks like a bit of burn difference, not great big difference but it is noticeable.

I believe it has something to do with the angles of the intake manifold and therefore the length of the intake path.

Just discovered a possible reason for the increase in temperature on the front cylinder, a leaky exhaust valve. The rear cylinder was also leaking but nowhere near as badly as the front cylinder.

The rear cylinder is lightly colder 20° C

Did you get the measurements from bungs welded into the head pipes?

Yes