The front springs on my 74 w200 need replacing. While they are not horrible, they're getting there.

I got an 89 Cummins parts truck (D250) that has nice rear leaf springs.

Could the rear leaf springs be installed on the front? Is it worth it?

Fronts are 48", with 24"/24" centered pins, rears are 52" with 24"/28". To get them properly lined up some significant modifications will be needed to the mounting. They will also give you a ton of lift as front leafs are darn near flat in their stock form.

Even if they would bolt up the spring rate is most likely much too low for the front. Typically rear springs are lower rate since their is less weight when unloaded. Secondary springs are engaged when the truck is loaded to attain higher payload.

Get them rearched and add a full length leaf. I used to have to do this to F250 ford 4x4, the front springs were crap, but after rearching and adding the extra leaf, they were good. Find a truck shop, they are more than capable.

Or, I have taken a leaf out of the rear spring pack, added to the front and done the same thing, cheap. Just need 2 sets of rear springs to get the same length leaf to add to the front. All you need is 2 new center bolts and new u-bolts,U-bolts may even be long enough to use over, but they are cheap so buy new ones. My 2 cents.