The rods in these late model 6's seem pretty stout. I have a 292 with stock rods that had been cleaned up and shot peened and assembled with ARP bolts. I have run the engine in my '56 Chevy 2 door sedan for several seasons now driving it on the street and racing it at the drag strip fairly regularly and not a hint of rod or rod bearing issues. When racing the motor consistently see's 6800 to 7000 rpm. The 250/230 rods should be even tougher since they are shorter and have a shorter stroke to deal with. Leo's book is the ultimate authority on that sort of thing - but that's my experience.

1964 Chevrolet C-20 Fleetside, Otis
1950 Chevy 1/2-Ton, Kirby
1950 Chevy 1/2-Ton Shortbed, Walter