Well spotted mate, yes ive compeltely stress relieved the block, ive removed all the casting marks and every sharp edge has been "broken" into a radiused edge instead.

I cant comment on how much difference it makes as its not like cossie engines where everyone has tried everything a million times before.

It might not even be needed, but im working on the basis of i am going to address every single possible point of failure as i dont know which ones are issues or not as i have no one to draw on the experience of sadly.