Those "spaghetti" 273 rods were the ones Mopar Performance offered with good rod bolts. They are quite sought after today for those that know what they are. What rods do you think the D Darts came with in 1966? Yeah. Those. Those little engines got spun the piss out of in D stock racing class. Reworked with ARP rod bolts with a good balance on the rotating assembly with modern lightweight pistons and I wouldn't hesitate to spin them 7K plus.