[Tom Broome]

Back to the original post. It's difficult to qualify OEM mass production rods. Small variations in bolt centerline between the rod and cap, how perpendicular the bolt (or nut) spotface is to the bolt centerline affect the repeatability when the bolt is torqued.

Back in the Buick days we would deburr a small spot inside the "H" beam of a Carrillo rod, just above the bolt thread exit. It's been too long to recall the specifics, but I remember it was significant enough to resize the big end. That's when I began to understand how touchy rods can be, and how important it is to maintain consistency between preparation and assembly.

The shop procedure was to hone the big ends individually since the rods run on split journals. It required a lot of attention to keep the stones and guide shoes from wearing in a fashion that caused barrel shaped housing bores.