Conceivable that the mechanic removed or loosened the lower dipstick
tube (the one inside the pan) and now the end of the diipstick flops around from the agitation and vibration
and contacts the crank. Lots of folks leave out the lower tube and have the same problem...although I dont know if a 326 specifically does.

If your dipstick flops, you're in trouble!

mike in tucson