360 flex plate

factory flex plates for MOPARS. Two sizes(depending on converter size, either 11" or 12"), two different crank mounting patterns. Used from 1962-up. On the 360, the converter had two weights each 1.62" x .75" x .380", for a total weight of 100 grams. On the 340, two small weights each .88" X .62" X .177". Hope this helps, along with the attached pdf. The 340 converter is not balanced for the 360, so either get as others have suggested, a B & M flex plate, or get a rebuilt 360 converter. The 340 converter stalls around 2400 rpm, and a 11" 360 converter typically will stall about 200-300 rpm less. Don't dump the 340 core, as they were and probably still are difficult to find. The converter shop I worked at all 340 converters were core in first, with NO exception.