ID these engine brackets please

Mr. Sinister said
318-340-360 Right side is all the same for A body
340/360 LEFT are the same and they are narrower than the 273/318 LEFT that are more common.

Would #1 & #3 be a pair of 340 for an A body ? #3 is to narrow for a 318.
Would #2 & #4 be a pair for an E / B body ?
Just trying to understand these.