[x33rs]

Something else you can do Lynn that I check with all Holley carbs here is flatness with the metering blocks.

I noticed you mentioned a large internal fuel leak. If you already checked the obvious (blown PV, transition slots not overly exposed, or dirt in needle and seat) and you're still having a serious flood issue, I find a warped metering block often a cause, especially on these 50 year old carbs. Meter blocks that aren't sealing properly cause all kinds of wonky idle issues and internal fuel leaks.

Holley used to make a tool to bend the meter blocks back into place. Yes sounds crazy but this was a problem even back in the day. I have one of these tools in a box somewhere I haven't found since I've moved but it's just as easy to chuck it in a vice.

What happens over years of cranking on the float bowl screws is that it draws in the corners of the meter blocks. If you run a straight edge across the block you'll find a lot of them bowed in the center. You can carefully chuck it in a vice in such a way to apply pressure and gently bow the meter block in the other direction, and let it rest for a few minutes. It's okay if it now bows slightly the other direction. It will push and seal in the center of the gasket better, and saves some of these hard to find meter blocks.

I also run a straight edge across the face of the carb, and often find the corners of the carb pulled out from the bowl screws. I lightly run a fine file across the face until I see the file contacts the entire surface, then clean and blow out all passages as necessary. I find this is most often the cure for old carbs that most people removed long ago for poor running problems they could never figure out.
Hope that helps.