Engine damage / 440 RB

Hi Guys,

built some sb´s up til now, no B or RB engine. Could need some support, maybe more in later stages of re-assembly ;-)

my friend called me, engine of his 73 coronet station died recently. I disassembled it today, found one rod bearing 90% gone, crank and rod damaged, bearing material all over. According to him oil pressure was ok, no overheating etc. - he´s a control freak and checks his gauges regularely.

What do you think caused this? Engine ran smooth for about 3 years, just a cruiser with occasional strip fun (i think never revved over 5000 rpm). Engine has got around 20000 miles since complete rebuild by a shop.

I do not know if this will clean up at .020" under. Is it possible to go even smaller on the rods?

Thanks for info

Michael