replacing rod bolts

When you press them out and press the new ones in it can/will distort the bore of the big end hence the need to resize.

When I built my engine the machine shop wanted $25 each to replace the rod bolts, resize and balance them plus the cost of the bolts. Also, it's not much point in doing it if you aren't going to go with a better quality bolt.

FWIW, it was cheaper to purchase Eagle SIR rods than to rework stock rods and you wind up with a stronger rod, more closely matched weight wise, balanced rod with floating pins.