Direct Connection RB connecting rods

The 3/8" bolts can be replaced with stronger 7/16" bolts so that's no concern. The main concern is how to balance.
The stock LY rod is 846g and the street hemi rod 1084g (from the FSM). I could not find any weight for the Six pack rod in the FSM but somewhere was said that it's around 33oz = 936g and that the hemi rod is about 35oz = 992g.
Looking at those figures and comparing with 1010g for these rods it seems that even the external balancing like the Six Pack uses is not going to be enough.

I suppose the Hemi crank is much heavier and has much more counterweight than the stock RB crank, since as I have understood the Hemi is internally balanced.

Whats the way to go to balance Hemi Forging rods with a stock RB crank and pistons?
I realize that the easiest and maybe cheapest would be to abandon the idea (and I probably will), but just for interest, how did they balance these Hemi Forging RB setups back in the day when these were the hottest setup for a RB?