Well, u could use the real early ones that were on the 69-70's. No exterior linkage. Different throttle cable.
They will give you some room. They show up on eflea as $andcast carbs quite often for $100-300. CR carbs will set you back around $650 and might be overkill on a stock motor.
I don't know if the CR or 77-78 carbs will give you some room.
Those who would give up essential liberty to purchase a little temporary safety, deserve neither liberty nor safety. Benjamin Franklin