if i weld the weights for my cast crank on a neutral balance torque converter is there anything to consider "heat wise"
just ground at the ring gear to avoid current flow through anything but the case?

weld away with a good weld in the hole unless its a lockup converter.

..anybody know what the weights weigh in grams on a cast crank 340 torque converter?

Two 25 gram weights.if you need the location of the weights I can send info.