Mike,
Thanks , that's an idea that I hadn't thought of, would need to check if it would clear the camshaft.
Not yesterday I line bored the block for the 1.125" bores and the .625" centre bearing mains, it's very similar to he Sealion setup but fractionally smaller. I kind of figured if it worked on the Sealion it would work here , very hard (impossible) to see what's happening when boring the centre main, I did the line boring on the lathe mounting the block on its sump face to a subplate on the cross slide, it was cut measure adjust etc etc
Regards
Mark