That is an interesting crankshaft, a Mark 25 with a steel reedblock where the rollers run direct between the inner surface of the reedblock and right on the center of the crankshaft. I always wondered why they didn't go that steel reedblock route itself instead of bronze and then aluminum? I have a 4 banger Merc crankshaft that uses the same system so its supported in 2 extra spots not found on regular Merc 4s. How much extra bearing drag comes with the extra support is a good question. The Alky Deflector Quincy Merc padded block engine was run considerably. Other old racers claimed it sealed and isolated crankcase sides better than standard labrinth groved reedblocks or the smooth face oil hole pressurized versions. I wonder how many Quincy Flatheads ever used this sort of bearing system?