over bore for Ford 711M or "L" block

I have been doing research on the maximum over bore that would safely work with the blocks listed above. My research indicates that the absolute "safe" overbore for each of these blocks would be 83.5MM. I have seen a Lotus Twin Cam for sale on EBay with an overbore of 85MM using the "L" block? Could anyone on the forum provide any information or insight on this topic. Thanks for your time and consideration. Jerry

over bore for Ford 711M or "L" block