The new pistons were within 5-6 grams so a HUGE miss match. Edited The compression height between the stock and the new pistons was a lot but the skirt was shorter from measuring centerline of the wrist pin. Both wrist pins weighed almost the same. These were DC 9.5 pistons in stock bore size. Came in Std, 0.030", 0.040" and 0.060" and were cheap at the time.
Something tells me the FACTORY balance was not near perfect by any means.
But this was a Truck 360 so no race car tolerances require.
You win. We all can go home now.