Hi Guys,
Sorry for the delay - I've been away for Christmas. The mechanic came round and adjusted the lifters as suggested. It seems to start and run all right, but I haven't taken it for a spin yet. He tried to turn the mixture and idling right down, maybe too much as it takes a bit of revving to start it now. I suspect because of the engine tuning that I'll have to put up with high fuel consumption. I don't know what a stock engine's like, but this truck is like a car to drive in terms of speed and acceleration. Thanks for all your help and I'll let you know how she behaves once on the road.