Mopar Muscle Association UK

I need to know the stock ride height at the rear of a a 67 cuda... then i should be able to work out how high my car sits from stock ......Then i can order my mono leafs.....with me so far?????... ........ Then from there i should know what ride height to order enabling me to get the rear down as low as possible.........still with me???/ Thanks in advance..I know this will be a bit of a suck it and see sort of deal but i need to start somewhere......