yes, clearance on pushrods may be a factor in bending the pushrod, but maybe not THE factor. I haven't worked on a BB for almost 25 yrs, so I don't remember if rocker shaft ends are marked to easily denote lube holes properly like a SB. But if you look at a FSM, the rocker oiling holes on each shaft are at 15 degree angle to the centerline of the shaft attaching bolts. Those oiling hole location is CRITICAL to properly lubricating those adjustable rocker arms. The oiling holes are supposed to favor the valve side of the shaft. If you find that they were incorrectly positioned, you MUST closely examine the bores of the rockers and bottoms of rocker shafts for galling.