With steel rods in aluminum block I figured on .005 to .010 block growth, so if I run steel rods I had better have . 040 cold to be safe. Al rods and Al block figure would go possibly the other way, so add .005 to .045? That would be . 050, which Al mentioned.
On those aluminum rods, if run should they show a little bit of scuffing in the big end? Looking for ways to tell if they have only been used for mock up as seller says.