[slowbird]

Originally Posted by PAUL K

When switching from a steel rod to aluminum rods you want to turn the counterweights down rather than drilling holes when balancing the crankshaft. Any gain you might of seen from the lighter rods may have been absorbed in windage losses due to the holes machined to balance the crank. You'll also benefit from the shorter counterweight.

If that balance hole offsets the gains from the alum rods, then the gain was so small it wasnt going to be noticable.
Besides that how does lighter rods increase performance?