I have a Ford Canada flathead C69, that is being rebuilt. I plan on reusing the factory iron heads and head bolts as my machinist advised against going with studs. I can't find much info on head bolts for this series of engines (pre 8BA). The engine was rebuilt at some point by an authorized Ford rebuilder using bolts, but what I find interesting is that there were three different lengths of bolts used. I see for the 8BA series only two different lengths were used (1.94" & 2.62"). I have qty 4 that measure 2.37" and seem to be located in positions 11 and 14 in the pic below based on the amount they protrude below the head surface as they match that distance of the other bolts which are also 1.94" and 2.62". My heads are marked as C7RA-A. Can anyone shed light on this "anomaly"?