273 Rods work in a 360?

If your pistons have the lock ring grooves, they should work fine with a rebalance as others have said. Before you pull the trigger on using the 273 rods, check with your machine shop to see how much it will cost to resize your 273 rods and fit the pins, plus end balance them. You may find that it is cheaper to buy new Scat I beam rods that are already balanced and come with new ARP cap screws, instead of fixing the old rods. I saved money going that route when I built my 273 a year or so ago. Good luck with your build.