I have already thought further ahead than that D. And yes, the mod to those centre bolts does seem like what I will have to do. But I will work all that side of things out shortly enough. I am not going to be able to mill too much out of the main bearing cap assembly as there is no steel it needs most of it for structural integrity, But I am going to have to sink those bolts enough to clear those heads. I was talking to my boss last night about it and he suggested a couple of good things, that I can physically shorten them by miles and make a new girdle that is wider and closer to the sump edges but that would be unnessicary as I don't need that much clearence, also (this will be the most likley outcome) I can sink the back 6 bolts, the lowest 4 only by 2mm or so, and then mill a bit off that area to gain some clearence.
But all that is a bit far off from this point to worry about. I pulled the rest of the motor down with young Mik and Nick there to listen to me crap on about the project and my apoligies for the smell in the shed, I did have a curry for dinner, and showed the guys first hand what is happening with it and the lads can't believe how easy I can move the engine around. It is so light. i washed the bottom end components last night at work and weighed the block.

14.41KG. Not too shabby.

As you can see the girdle itself is reasonable straight, but the center bolts are higher and underneath the casting does change. If they are sunk the ribs will get thin but there should be enough surrounding meat to keep its strength.
As for the other motor I would rather compare apples with apples. That motor has steel main caps so the problems will not be the same. If they were alloy it would be a different story. I have to deal with what this engine has. There will be no extravagand modifications on this motor. It needs to remain as standard as possible. I will spend any money on the outside getting things to fit.