The rods are floating pin, same as the early 318, 726 grams. Later rods which came out with the 340 were the 496 or 645 rods, thicker shank and weighed 758 grams.

Both are at least 100 grams too heavy.

I'd keep them with the block and pistons, if you sell the crank. BTW, the 273/318 forged crank is different than the 340 crank, as the 340 crank has lightening holes drilled into the #1 and #4 throws.

R.