Hi Mike, very keen to follow your findings. I also have an engineless 406 and have considered a Rover 2600 repower as the engines have very little value here in NZ and are probably quite reliable and a good cheap solution in the interim while we wait for the correct engine to present itself. I can be contacted off-line on
desmolloy@gmail.com if you care to compare notes etc
Des Molloy
Golden Bay
New Zealand