HD springs

I'm Trying to figure out how much lift you get when you upgrade to HD coils and HD leaf springs?

That would depend on the manufacturer. Some from JC Whitney for example will lift the rear and not the front. Others will keep the stock height. You have to look at it case by case and I don't have enough information to do that, nor do I know anyone who does across the industry

I got some HD coils from Auto Zone that are .6 inches thick compared to the .5 of stock. They gave me 2.5 inches of lift up front. I'm going to assume they will settle to about 2 inches of lift. For the rear I'm looking at the "extreme duty" leaf springs from quadratec. They have 7 inches of arch and i think stock is 4 inches (correct me if I'm wrong). So I'm looking at 3 inches of lift in the rear. Does this all sound right?

It sounds right if the spring rates are the same. This is one of those areas I was talking about. I would ask a tech support if they have one about that. And remember that lift is determined from the stock position at the time of manufacture. At that time, the rear of the XJ was taller than the front by almost 2". See how muddy it can get?

Yea true