If these rods had pink on them it is long gone. I've heard so much controversy over these things I was hoping to get a definitive answer. I do believe the 70 rods with the X on them are pink rods. I'm not sure about the 69s with the O. They originally came out of a 69 Kingswood Wagon with a 300 hp 350. They are identical in apearance to the 70 rods with the X. Any help would be appreciated.
Original late version 1968 and 1969 Pink Rods #3973386 are shotpeened select forgings that are Full Floating on the wristpin and the small ends are lead babbited, they have a "O" on the cap. The small ends have no oiling hole. They are easily indentified by the pink paint that was on the beams, after years of use it also appears like dull white? The caps of original 69/70/71/72 pink rods are a different colour as the rod is shotpeened and the cap is not. This is easily seen on known original pink rods. By the way 1970 and up rods are pressed pin.
"O" rods that came in trucks and passenger car engines have the same "O" designator but are not shotpeened and have pressed pins and no pink paint.
The Original "O" pink rods were discontinued from GM circa 1973/74 and the part number was superceded to the 72/73/74 version Z28 rod, which has a "B" on the cap and is a pressed pin rod, they also appear with the Pink paint. I have taken apart many Z28 302/350 and Corvette LT1 & L82 Engines over the last 40 years and this was allways found.
I personaly believe that "X" rods did not appear from GM until around late 74, early 1975, and this comes from working at a performance machine shop for 10 years in the 70,s, ( 1972-1982) and a Corvette Shop for 20 years ( 1985-2005) and the first time I saw "X" rods was around the mid 70,s in truck and passenger car engines. There is also a version of a pink "X" rod and it was installed in L82 Corvette engines from 75-79 and it also had the pink paint as well as brown ( or tan ) and orange from time to time.
A performance rod was offered out of the GM power book in the 70, and 80,s and these rods had the pink designator paint, I believe GM did that to identify the shotpeend surfaces. These are usually "X" rods.
I constantly see so called pink rods on ebay and just laugh when they have the applied pink paint and "X" on the caps. I can email some pictures of original 69 Pink Rods as well as 72 version Pink rods if any one is interested.
Hope this helps.