Pete Air Leaf

It’s fine. I have same suspension on my triaxle 379.
Your truck has a rake to it just like mine and every one else’s. I have more height in rear than front.
Yes it has leveling valve but if they were close to same height, your rear axle would be off the ground
Only has one leveling valve located at rear

 

VIN please......

It appears you have Air -Trac and not air leaf. The ride height needs to be measured from axle center to the bottom of the frame. If set on level ground your bag height should be the same from front to rear drive and be close to the same height. My first thought is you are set too low. Should be 10.5 unladen. Post Vin and I will double check all this info for you.

 

I have air trac. Looks like mine. Defiantly not low air leaf

 

What is the issue you are having where you are questioning the height difference? It’s normal. If I wasn’t already kicked back with my boots off and a cold one in my hand I would go take same pics of height difference

 

There is air leaf, low air leaf and low low air leaf. Air leaf was the only option in 1986. Low air came out late 87. Low air also uses a Z spring. It is common for the front not to be as tall. Stretched u bolts and worn frogs cause a lot of it. If the suspension is constantly working when sitting still you have stretched u bolts or a cracked housing