4640 is a 750cfm Carb - 440 HP

Nothing wrong with that carb especially if it’s in good shape and you want to install the flat metering rod covers , and then convert to the Edelbrock metering rods/jets

That way you can test and tune the easy way

Watch for the hot idle compensator and vacuum , I like to block them off with my own gasket

Also float level and drop is critical

And the accelerator pump leather drying out

I can’t remember what Edelbrock accelerator pump I ended up using / WAS NOT the Blue one

Flat Metering Rod Covers

Edelbrock

.101 Primary Jets - .065X.052 Metering Rods

.107 Secondary Jets makes for a good start