I know that the 221, 3.6 crank is steel, but I'm not sure if the 188 (3.1) is too. I had the 221 crank long run welded to increase the main journal diameter to fit my 250, a process the machinist said he wouldn't do on a cast crank.
For the record, my measurements of my last 221 block gave it an 8.465 deck, 5.14 rods, and 3.46 stroke for a real crappy 1.485 rod:stroke ratio.
The 188 was 2.94 stroke, and a 5.47 inch rod, and used the same block, so it should have been a 1.86:1 ratio. As the Italians have long known, reduce the stroke, increase the revs. People love revs.
My Falcon project is that 6.275 inch rod, 3.46 stroke steel crank into a 305 Chev pistoned and valved 250. Phew! Rod ratio is 1.81:1. I hope this will be more inspiring full flight as a 228 cube machine!
Oh, Matt (I'm being a smart ass again...or just an ass):- (Using the standard bore of 93.472 mm, and the various strokes)
221 was really 3618 cc's, stroke is 87.884mm, rod 130.556mm
the 188 was 3075 cc, stroke 74.676mm, rod 138.938 mm
the US 200 was 3269 cc, stroke 79.4mm, rod 121.361mm
the Oz and US 250 was 4089 cc, stroke 99.314mm, rod 149.479 mm
my 228 is really 3729 cc. (its got std size 94.894 mm forged pistons), 159.385 mm rods.
Hands up who likes metrics. Not me. French people had other better ideas like revolutions, art and foxy ladies!