273 commando rebuild question

Rebuilding this little 273 Commando engine The goal is low budget and keep it as original as possible.

Today I picked up some new Egge .020 over pistons and as has been discussed in other threads they are lighter than stock. I have a decent postal scale that says the stock pistons and pins are 750 grams each. The new pistons are 682 grams each. So the new pistons are 68 grams each lighter.

That got me thinking about the rods. The stock 273 rods I was going to reuse without having any work done to them. They weigh in at 728 grams each. I also have a set of stock 340 rods that have ARP bolts, been resized, and the beams cleaned up a bit that weigh in at 748 grams each. They're 20 grams heavier than the 273 rods.

Not knowing a lot about the balancing. I usually just take it in and say balance it. In this case I know it is still going to need balancing regardless of what rods I use. With either combo it appears to me the bob weight will be lighter requiring balancing the crank is that right?

My next question is should I keep the stock lighter 273 rod? Or should I put in the better 340 rods?

Also noticed there is a couple grams difference on a couple of the original pistons and the new ones. What is an acceptable difference in weight between the 8 pistons and and even the 8 rods?