440 RB stock Pistons

If the pistons are off the rods, you have a great opportunity. But yourself a digital scale that reads grams that will go to the highest weight of your rod or piston. I checked weight on each piston, rod and wrist pin and recorded. You can then match rods, pins and pistons to the get the most consistent weight across the set. Doing this simple mixing/matching, I achieved less than 3-gram difference from the heaviest piston/wrist pin/rod to the lightest. This was on a small block Ford and even with ~220@ .050/.517 lift cam, the engine idled rock smooth and was great running little engine. Minus the crank, you're balancing the rotating assembly yourself for the cost of a digital scale. I think I paid less than $50 for one I bought on Amazon. Then take each matched piston/wrist pin/rod to the machine shop and have them assembled.