If you were to learn how to tune/adjust carburetors you would never be sorry for having spent the time learning to do so. The theories and principles involved allow you tune your car for your specific needs/wants/circumstances/requirements no matter how unique. Being able to do so yourself means you are not at the mercy of ANYONE else and it is extremely satisfying.
Besides,no new carb out of the box will be perfectly tuned for your application with out SOME dialing in. While carburetors might be becoming more and more obsolete, the theories behind them are not; their principles directly relate to fuel injection.
Heck, if nothing else, by tuning your Holley 600 to your liking, you would therefore have the money that you spent on the 390 to buy other goodies.
