The Holley carb is easy to rejet, all you need is the float bowl gasket and a screw driver. (and the correct jet!) Finding the correct jet size for your conbination is always the challenge, for what you have discribed, I would say a #54-55 jet would be about right.

Thr Carter BBS 1 bbl carbs are more of a challenge because these have a floor jet and a step-up rod which are hard to find these days. I usually work with the step-up rod size alone unless the WOT is way rich.

Sometimes you can get the BBS to lean-out just by getting the step-up rod to drop down into the floor jet a little more.
Take the top off the carb. and measure the diameter of the step-up rod and the floor jet hole. Also look at the ID numbers stamped on the side of the floor jet. (write this information down)
Look at the "hook" at the top of the step-up rod and bend it upward, so the rod can drop deeper into the floor jet. You can also bend the mounting tab on the step-up piston downward, to drop the rod. Test drive the car to see if that helps. If still too rich, go on the hunt for the bigger step-up rod or smaller floor jet.
DD