Now that was a username that I would have immediately recognized as being you

Thanks for the explanation on the liner swap, so if I am getting you right, the (ABC) piston and liner of the SH 55 engine should be a possible swap into the GO GH56 with some minor and easy to execute mods like a headshim? Kewl!
I don't need one yet, but it is good to know there is an alternative/it can be done.