[flatheadkid1]

It looks like there is another obstacle to overcome in the rear main seal area. The 36 LB rear main does not have the die cast replaceable insert that the later engines have. If the 36 LB rear main is used in the conversion a ring will have to be added to the merc. crank (pictured on the right) to create the labyrinth seal.

Did 37 blocks have the replaceable die cast insert? If so it may be possible to use the 37 rear main cap (align honing required) with later 59A die cast inserts in the rear main cap and in the block facilitating the use of a rope seal. I don't have a 37/38 rear main cap to test this overly optimistic thought.