The "aftermarket" Mopar Performance rods were made from 4340 steel. There was the standard/HD 340 based version & a "lightweight" 273 based forging. I did have some of the lightweight rods and they had "Mopar" cast into one side of the beam. But there may have been more than one vendor during their run and I never knowingly saw a standard/HD version. I have pics but can't access them from work. Then there was the earlier, very heavy "Hemi-footprint" rod which had it's own forging design.