Can anyone offer up their experience with driving on different spring rates on the rear? Just what spring rate do you have and how it rides/hauls. I'm looking at some springs on eatondetroitspring.com and I think I have it narrowed down to two:

ML4401 with a 150/274 spring rate, 1475Lb qualifier
and
ML6327 with a 205/370 spring rate, 1950 Lb qualifier

I have no idea what the qualifier means if someone knows.

 

I run a '78 F250 4WD. When I first got it equipped with aftermarket overload springs in bad shape + dead shocks. It rode horribly. New "standard" F250 springs and good parts store gas shocks made a huge difference in ride and still good for hauling.

My local spring shop sourced the springs and is a great resource... including custom setups on other projects.

For your situation, not sure. What model truck, how equipped and how do you use it? That would have a big impact on spring choice.

 

79 F150 Custom Explorer 460 C6 4x4
Currently has Superlift leveling springs and 2" lift shocks on front or at least it will when I finish the passenger side, rounded off a bolt in the spring perch
Rear is stock leafs and replaced at one time by PO but currently dented and rusted shocks.
My current use is for light off-roading for camping, loading the bed up with scrap to haul off or towing cars. I do see a 17' ski boat in the future though.
Because I don't do much truck stuff with my truck I was thinking it would be best to get progressive springs and some soft bilsteins for the rear.

 

Can you post a link, picture or drawing of the springs you are looking at?

I guess the first set of numbers is the spring rate (lb per inch deflection) for the springs when on the first stage and second stage when the progressive feature starts working. The second set of numbers is spring capacity in lb.

The attached link suggests the stock spring was rated for 1,650 lb. No spring rate is shown.

The first aftermarket spring you listed sounds a little light to me for hauling & towing duty.

Personally, I would get a decent set of shocks and run the springs you have. See how you like it then decide if upgrade is needed.


1973-1979 Ford F100, F150 4wd - Leaf Spring (Rear - 4/1 Leaves) [43-567] | $148.95 | SD Truck Springs | Leaf Springs, Helper Springs and Suspension Parts

 

Unfortunately the link only brings you to their search function, but here it is:
https://www.eatondetroitspring.com/o.../parts-lookup/

They do however have a set listed as handling 1650lbs with a split rate 167/315.
I'll go with that one. Thank you for the help.