Question on 360 crank balance

Hey guys, just got my 360la crank back from the local machine shop, he said I needed a neutral balance converter. When I brought all the parts in to get the crank balanced I brought a b&m 10236 and a stock flex plate and he said to use the stock flex plate with a neutral balance converter. I was just wondering if that sounded right or not. I thought with an external balance engine you needed counterweights at both ends. He also told me the end balanced out at 3g and the front balanced out at 52g, whatever that means. And to answer any questions I just had him balance the crank with new rods and Pistons and yes it's still externally balanced.