Doing a "de-smog" will eliminate many potential vacuum leaks but will not do anything for the carbs if they have other problems. Switching to another carb set up unless you are adding a supercharger kit is not a practical option for the Valk. The six carb set up on the Valkyrie is very reliable & well engineered, it's really not that complex. You will be MUCH better off fixing what ails the stock carbs than trying to toss them aside & going some other route. If the Valk 6 carb set up was unreliable I'm sure by now someone would have come up with a practical alternative fuel system... I haven't yet seen one!

Besides, the 6 carb set up is one of the main features that makes a Valkyrie a Valkyrie!

Was this bike sitting up for a while or showing any other symptoms? More info will help.
One to two years of sitting made this mess of this Valk carb bank.