Looking at the Hastings catalog page, it appears there are several combinations of ring groove widths for the 4" bore M6330 see lines 82-84 of the page.
http://www.hastingsmfg.com/RingFinderMasterDetails.aspx?AppMACD=CONTENG%20&AppMOCD=CONTINENTAL%20Engines&AddText=(Listed%20by%20Cylinder%20Diameter)
More ID information
http://www.smokstak.com/forum/showthread.php/showthread.php?t=31422
Line from cam bearing catalog
330ci/5.4L 4.000 bore - K6330, M330, M6300, M6330, M6338
Paul
I think we have a power unit like that it may be better just to get a parts motor.You could call Albert Simacek and ask him in the evenings 402 268 6321