Thanks people for all your views, I drove to work this morning (very carefully) and it felt frightening , the steering was so tight it felt like something was going to "give" at any moment and lose steering ....but it didn't . So after work I went to the garage I was after using and it was closed ...I then drove to B&Q and picked up a blowtorch and made it home ....real tight steering .....took the manifold off heated it up and beat the living crap out of it , figured 5 or so mm would have been enough ....but then another 5mm ....and another couple for good measure, didn't want to have to take it off again , put it back together .....1-2mm clearance ....good job I manipulated it as much as I did .....1hr 50mins from start to finish