We must remember that Flatheads were made at least three different Countries
UK, USA, Canada .... Australia too?
However Mercs were only built in the USA and went into the T16s, for some reason we wouldn't accept them, although we did test them. The wartime manual I have lists all Flathead types for UCs and Loyds and if you go through the cylinder liners list it says all versions can take the Dagenham liner. If any were the 95/100 BHP version they would have the larger bore to give the 3.8L capacity.
HOWEVER wartime manuals on UCs must be taken with a pinch of salt
