Terry,
That's a good question. I did what you're contemplating. My Solex seemed to run fine, but I could never get it to work right when adjusting the PSI to the recommended 1.5 to 2 PSI. I had to deliver the full 4-5 PSI flow, or it would starve for fuel. My result...It always ran rich. I must note...I live at 5,500 ft above sea level.
I wanted to use the original Carter WO, primarily because of the way it looks, but also because this was the original design.
For you, it may come down to the condition of your Carter. If it's got all the linkages, the throttle shaft is fairly tight in the bore, you don't have any cracks in the base, or any obvious damage, then I say, go for it. A rebuild is a little intimidating at first, but there are some very good rebuild guides available, and ScoutPilot (resident expert) can really help you be successful.
My opinion...I Love the Carter. If clean and rebuilt, it will improve your performance.
Tim