andrew what length bolts are required? I'd imagine you would need to cut them down to size as the fule tank may foul them when put back on.
spoke with a friend who is a technical teacher and fabricates stuff etc. He said best bet is to get U style bolts which will wrap around the chassis. He was telling me that by drilling the chassis even though the inserts are in the chassis with the bolt there will be considerable strain on it as the vehicle moves.he said if you can avoid drilling the chassis
www.tubeclip.co.uk/Pages/UBolts01.htmlmy mate reckons this is what i should be going for. He reckons 2 of these on each main chassis rail and the rest to be done by spreader plates, nuts and bolts.