johnhorgan wrote:

Conclusion- Yes fitting the 2.7 to replace the 3.0 works.

There are a few differences which make it awkward;

The engine breather system is different and not interchangeable without modification.
There is a different outlet hole bored into the 3.0 block, which is impossible to replicate on the 2.7
The 2.7 breather cannot be used because the 3.0 injection pump is taller.
I just connected the breather hoses together and routed them to exit into the atmosphere under the engine.

Some of the bolts that retain the EGR system have no mountings on the 2.7 block, but they stay on fine with those that are available.

Some of the turbo mounts are missing, but again they stay on fine.

I have probably forgotten to mention a few things, but I will try and answer any questions.