Body mounts

[Choosing a name is hard]

Hi all
I bought a 1970 c3 big block it was someone else’s project before I got it . The chassis with rebuilt engine were separate to the body . I have now had the car running and fitted breaks exhaust,clutch . This weekend we lifted the body back on . I have the factory assembly manual and it says the body mounts ( I have a tub full of new ones ) in the middle are the same but the front and rear are handed L/R the right are the same as the middle ones but the left F/R are different .Dose anyone know what the difference is please
Pete

 

[Choosing a name is hard]

Here are photographs of the body mounts . I have 6 like the right hand one ,plain with no raised Center . And two like the left one with a raised Center . According to the assembly manual the raised ones are for the front and back points (position 1 and 4 ) on the left hand side .I wonder if anyone knows why and if it matters which way up they go ?