on my project Ranger I got some leaf springs off a donor and it has leaf spring helpers/add a leaf kit, do I leave them or take them off and save for later when I may need them?

 

The add-a-leaf springs will give you a rougher ride if you don't have a load in the rear. It will also sit higher in the rear with no load. I used to run add-a-leaf springs on my 89 STX but it had a fairly heavy shell on the back to keep a reasonably smooth ride and level.