dual quad low profile?

OOOOOOOOOOOO, pardon me.
In that case, old AVS and AFB carbs can have the base drilled out to fit if need be and new Edelbrock AFB/AVS carbs have both holes for both patterns.
Again, sorry.
But there is no Slight spreadbor carb. It's not the carbs mounting holes that declasre it spread or square.