on the model WD/CO 350, that has approximately the same bottom-end as the model C, there are hardened steel thrust-washers on both sides of the big-end bearing, and after tightening, side play on the big-end bearing should be between .010 - .020 in. (end float for crancshaft after assemby is .005-.015 in.). I suppose the same goes for the model C. I think Hitchcock has these washers in stock.
Ludo