Air shocks enough?

[coloradodave]

So when the car is loaded and you air up the shocks, it still puts pressure on shock crossmember. Do difference.

I assume you meant to say NO difference? Actually, there is a big difference. The air shocks give a 'boost' to help level the car so your safety chains don't drag, your headlights actually light the road instead of birds in the trees and help put some load back on the front end so steering is safer. THEY ARE NOT DESIGNED TO CARRY THE WEIGHT OF THE CAR FULL-TIME, INCLUDING WORKING AGAINST THE LEAF SPRINGS.
I'm not guessing on my answer. I sold Gabriel Air Shocks at the speed shop for many years. I can't count how many customers tried to return them after doing damage to their cross-members or cutting up tires because the air shifted in a corner. (I know, you can separate the lines.)
Used as intended, they're fine. A better choice for towing are Air-Lift airbags, which are designed to 'boost' but connect between the frame and axle housing, not the cross-member. However, they WON'T do what the OP wants to do...

 

[64SF]

You can buy a leaf spring helper from Summit for under $40.00. It lifted my 64 Sport Fury about 2 inches. It's a short spring not to difficult to install, it goes between the leafs.

 

[Mike67]

My Gabriel Highjackers paperwork states 'not' to run them without at least 'some' air in them. I keep them around 40 psi. Rides well and provides a nice stance (up about 1.5"). Not driving it daily (like it was in 60s & 70s), it will be fine.

Ya I didnt mean all the way deflated...

 

[Centerline]

I believe mine said to run them with no less than 25 psi.

 

[triggerfish]

seeing what the general opinion is here. will a good set of air shocks such a highjackers be enough to lift the rear of a 64 fury? or will I need some superstock springs as well? im cranking the torsion bars up in the front and hope the air shocks can handle the rear.

thoughts?

As many replying to your post said, shock mounts weren't designed to carry the full load that leafs do. My 64 Belvedere had air shocks when I bought it because the orig leafs were weak. I quickly got a set of 1" over stock height springs from ESPO and ditched the old air shocks. Car now handles great & rides much better. Couldn't be happier.