Crankshaft differences?

Well, here we go again.  Another parts conundrum!  I've got 2 different, early, integral counter weighted, crankshafts.

This one from my '46, engine # 16634:

This one out of a '47 engine, #108211:

Notice the rectangular bosses on the throws of the '47 crank.  My '46 crank doesn't have these, but the throw & counterweight forgings are just a little bit beefier.

The '47 crank has a casting number "638121" (same as the Willys part number), as well as a "W-O 56" casting.  The '46 crank has neither, but has other alpha-numeric casting identifiers.

Now it gets confusing.  The '47 crank came out of engine #108211, which is well beyond the change to bolt-on counter weight cranks!  It is a 641087 block casting w/gear drive cam, but the crank nose is oil drilled for a chain sprocket, as would be expected for a non-counter weight chain drive crank.

So the question is:  what kind of crankshaft have you all found?  Does anyone have one like the first photo?

Sean




Edited by sean - 28 Mar. 2009 at 2:37pm

the crankshaft in the 641087 block stamped "special" that i posted last year has a crank like #1 photo...a friend of mine had that engine redone for his 3A, and the machine shop told him that occasionally Willys would pull engines from the assembly line (engine assembly) and "test" different procedures, one being the micro balancing of the rotating assemblies.... the crank in the engine i mentioned only had 2 very slight indent drilled weight reliefs in the whole crank....