I worked on a Cosworth Vega in the '70s and they had what was referred to as a small journal, 6 cylinder version of a Z28 (or pink)rod. They were subjected to peening and magged. What I remember is that they looked a lot like the ones you are showing, but 35 years does cloud the memory a bit. We turned that motor near 8grand repeatedly. The aftermarked sold the rods under the same part #s as with the Chevy11. Built and ran a few Chevy11s in out 2.5litre boat but always went to the after market with them and remember the notes referring to the Cosworth.