1971 340 L2316 pistons stock, modified or damaged?

How many are damaged? I have set of those in the same size if your worried about reusing them.
You could probably polish the damaged areas, make sure the rings move freely and replace the rods, or at the least have them checked. That pistons quite durable.
I also have some stock rods with arp bolts ready to go.
Valves need replaced if that was done on your engine, cam checked, pushrods.
This could get expensive.