Comp cams xe268h for 318

AFAIK; as far as I know.
The early rods are lighter than the 73 ups, maybe as much as 100 grams.
Therefore to maintain balance, you would need the matching pistons and crank.

9.6 is a nominal figure. It only exists on paper and in the imaginations of men..... unless someone has cut it to 9.6,lol.