I completed the conversion with the Dura Ace 7900 DT 10 speed shifters. I scored a 12-30 6700 cassette and a Shimano 105 5700 rear Derailleur. I got them cheap at the local Performance bike shop that had them on clearance for their store closing. I already had a 50/34 Vuelta crankset in my parts bin. I forgot I had that.

Set up and adjustment was a piece of cake. I did a quick 10 mile ride and all is well. I have a Hill climb ride tomorrow, so I'll see how it does.

Thanks everyone for all the suggestions.