Icon IC 743 piston weight incorrect

Yes, but it requires some very accurate dimensions and computations of centers of mass, etc.. I have not ever worked that all out. IIRC, on those sets, the Magnum takes the middle sized weight, and the LA360 took the largest and the cast crank 340 the smallest. So there probably is some weight to be added in that largest weight. Tacking weight on at the back is easier. IIRC, the Magnum flexplate has a pretty wide weight under the starter ring.

I can tell you that with a 230 gram bobweight drop on an engine, the shop had to drill 81-82 grams out of the crank throws. (Or was it 82 in-oz??? The shop was not clear if it was grams or in-oz, and I did not measure it.) That was about a 1-1.25" deep hole in each end throw of an LA cast crank.

So with an 80 gram bobweight increase, it will not take a lot of physical mass.

Oh one more option:

• Drill out weight inside the crank journals for 1-2 and 7-8 journals. That was done on 340's and is done on SCAT 4" cast cranks; it effectively cancels out some of the bobweight, and is the equivalent to adding heavy metal to the throws. I don't think 80 grams of cast iron is a big hole, but it is not hard to compute. And if it is off-centered a bit towards the outside, it can be smaller.