A 750cfm Edelbrock isn't too big for a mild 360 small block. Mine runs great with no issues at all. Any carb in the 600cfm-750cfm range will work as long as it's properly tuned. I prefer the larger carb for the top end power gain/advantage.
yeah, 500 2 brls came on some stock 360's, thats a lot bigger primary than this 770, let alone the secondaries are only feeding what the engine will pull.
too big?
NO.
every cam'd 318-360 i ever run needed a shooter/pump cam tune, the automatics needed more cause the 28's that came stock dont do it.