Technical Leaf spring sag?

Just curious of anyone running into their leaf springs sagging. I have the original leafs on my 60 falcon, and have already radiused my fenderwells using them. I would however like to get some new springs and bushings for it, but don't want it to jack my car up as the fender gap is right where I want it.

Some say they shouldn't sag very much, others say they do. I don't want to spend the money and not be what I want

 

Remember my Dad bought a used 60 Falcon way back in 66 & the springs were sagging bad when he got it. When he replaced them it had what I thought was a very cool rake to it.

 

My Comet had the original leafs on it. I managed to break the right spring pack right in front of the axle coming out of a parking lot.

If new springs make it too high lowering blocks are easy or buy lowering springs if its definitely sitting lower than stock now?

 

I remember when i was a kid in the late 70's, early 80's wondering why all the mustangs and falcons were lower in the back than the front. Seems more prevalant in those cars than others.

 

Yep, Falcons and Mustangs are Famous for the stock leaf springs sagging. IN 1971 I put longer shackles on my sister's 66 Mustang just to get it back to stock height. In my experience, new springs bring these cars up around 2" from original sagged out springs.