[Tony Smith]

And before we get that far, is there actually a problem with the 8BA sump?

I measured the 99A sump to be 8 1/4" from the gasket surface to clear of the drain plug, while 2 of the 8BA engines I measured have a sump depth of just a tad over 8", marginally better than the 99A. The 2 engines I measured are Canadian 1951 C1BA blocks with car sump pans. Admittedly, these place the drain plug in a different location to the 99A sump, which might present a problem in a Carrier hull, but I'm sure there will be a version of an 8BA sump pan with the same drain location as the 99A pan.