That's a little different than you were talking about before. Went from factory iron, to W2s, to W9s? Wow. Way too much head for what you are intending to do. IMO, big mistake. A 9.5" convertor with a moderate stall and gearing will be horrid, idle's going to suck, as will low rpm response... the reason those engines make power so high is a combination of the cam and heads... Just changing cams will not go too far in lowering the power curves because the engine is going to have to reach 5K rpm to even begin to use that port. I'd want to see the heads flowed long before I said anything about a cam. Think about it... you are talking about 45-50% gain in flow over 260cfm heads. I think you should seriously rethink your approach.