Wrong cam/converter combination on the 340

I have a stock 68' 340 motor on my 1971 duster. It was basically handed down to me by my brother. He had some mopar purple cam and single plane intake before. I wanted good street manners along with power from idle to 5500rpm. I've since installed a dual plane edelbrock intake manifold 620cfm holley carb and 2500 converter. The rear gears are 3:55 and the transmission is a stock 71' 727 torqueflight. I wouldnt mind changing to a different converter. Can anyone recommend an excellent cam and converter based on my intake and car and rear gear ratio? I don't know the specs on the cam and my brother forgot. Thanks!

The issue is the high lited texted. First, what dual plane intake and actual carb is it?

The second set of high lited text shows that you have a "Stock tranny and yet a after market converter" OR is that a stock high stall unit?

The frank Lupo sugestion is a good one but you must be on the ball with what you have exactly.