Does anyone have advise / drawings etc on modifying rear suspension to take Sierra IRS using fabricated upper and lower wishbones and modified Sierra hubs. Blackburn area.

Donald, have a look and search in the chassis section and the running gear section...I've seen this discussed a lot in the past...many work from the Avon book...

I'm originally from Preston BTW.......good luck and welcome to the madhouse...

I have found a few variations on the subject here; http://locost7.info/index.php
diagrams and mesurments.