I have question concerning ride heights. I am new to modifieds, I have raced stock cars before and everything I have seen on a basic setup says to set them @ 6in. If I set it on the rear this will only leave about 1 from top of the rear end tube to the bottom of the frame? Where are these measurements being taken? And is this an realistic set up. I am running a 225lb spring on the left and 175 on right.