Thanks for the comments guys . I've been looking at the big bore set ups that are available from various people . It will probably work out less costly in the long run to use one of the complete big bore set ups which are currently sold by DYNOMAN ,Cycle X and APE etc .
Scottly, the cut off piece of crank was done for convenience . It had knackered journals so I used it to practice doing the sludge trap mods on , and also it's easier for my mate to handle for when he makes me a starter nut .