The 2.1 L crank is not counterbalanced.

There are different opinions on whether to counterweight or not.

I chose to add counterweights to my stock crank because of the benefits that
they add: double the bearing life, smoother revs, more power, stronger crank,
better oil control, (www.geneberg.com tech> crankshaft).

The only down side is the time it takes for the counterweights to be added.

It was only $150 more the counterweights and when divided by the estimated
mileage it cost less than a penny a mile, 0.001 cost per mile for 150,000
miles (for 200,000 miles it cost only 0.00075 per mile) (300,000 miles cost
only 0.0005 per mile)

If it is in your budget, I would add the counterweights.

As far as the 1.9 rods Vs the 2.1L rods, if you have the complete 2;1L rods
use them.  They are matched to the correct length and pin height for the 2.1L
pistons and the increased stroke of the 2.1 L crank.

If you have one that has a bad journal, IF it is not Blued, burnt or bent, it
can be rebuilt and work fine.

Demello can rebuild a rod and them match the set to balanced end for end.

They might be the same length and be interchangeable, I have not compared the
two.  Boston Bob would be able to give you more info, but I would suspect
that they are different for the different strokes.


Robert