I have a 2012 6.7L F250 FX4 Lariat. I recently added a 3 hole custom dog box sitting on a 6 foot custom 2 drawer system. The whole rig is made from aluminum and stainless steel. It probably weighs 500-700 pounds. Some days my truck looks like it's sitting level. Other day's it looks a smidge low. If I hook my utility trailer with the Polaris ranger on it, it's definitely an inch low. I don't want to do airbags. I've read about "adding a leaf" and if you go that route, add a "long" leaf vs a short one so as to maximize driving comfort. What's the best route to go on this or just change the rear blocks to F350? If I change the blocks do I have to get longer shocks?

Thanks

 

I did this not too long ago, so it's still fresh in my mind:

I grabbed a readylift rear block kit 66-2014 their PN, and swapped out the rear blocks and u-bolts. Did not bother the shocks at all, and no issues with the driveshaft angle.

Super easy job. If you can be patient, you can probably find some 350 blocks and bolts for next to nothing, but the readylift kit was less than $200 shipped, iirc

 

I did blocks on mine, and it caused a horrible driveline vibration, so I ended up having to go with airbags, which was a disaster. They're working now, but I really don't like them. If you can get away with the blocks, I'd go that route, as my truck looked a lot better for the week that they were in. Otherwise, I'd go with the add-a-leaf. My brother installed a kit on his '12 Crew Cab long bed and it has worked well. It was a spacer in the front, and two leafs on each side in the rear. I believe it was from Pro Comp but not 100% sure on that. No noticeable difference in ride quality with the extra springs.

 

to be clear I am not trying to level the front end but rather want to raise the rear end up slightly

 

Understood. The PO of my truck "leveled" the front, which actually gave it a very noticeable reverse rake. I lifted the rear to re-level it out. You're going to lift the rear of your truck with the taller blocks regardless of whether your fronts "leveled" or stock

 

I'm in a similar situation. My 12' F250 sits pretty level unloaded, and when I load my 200 gallon skid sprayer it squats way too much, even only partially filled. Add the tongue weight of my trailer and its awful. General Spring has different add a leafs for different weights starting about 900 lbs. They would slide right in the spring pack. I was also considering going the multiple add a leaf route, I think Skyjacker and one other do this, but it also requires slightly longer ubolts. They claim this helps the unloaded ride. I want to keep it as simple as possible and not totally ruin the unloaded ride. BTW, I switched out to the taller f350 blocks in an 03 f250 and the ride actually got worse.

 

Yeah, the more I think about what CB is saying, and reading into your issues, I'm thinking y'all need to look at improving the springs moreso than the blocks. Me? I rarely haul/tow anything (poor truck has a sheltered life) so the ride height being level was my biggest concern.

Do some reading and research, plenty of useful info on here, I don't think y'all necc. need to go airbags, but minimum leaf spring helpers/upgrades, above and beyond mere blocks, imho

 

Personally, I like the flexibility of air bags. I had them on my 04 and on this truck. I can pump them up when hauling my fifth wheel or anything heavy, then air them down for a good ride when not hauling.

 

I'm hoping a spring recommendation will give me a bit of a lift without making the rider harsher (ie I'm assuming a partial fill of air bags or a short leaf addition would make it ride worse)

 

I just had the local spring shop add 2 pieces of steel in each spring. Both are rated at 1800 lbs above stock. They work great no issues with drive line or shocks and they raised the rear height by 2 inches. Cost was 400 bucks done. I hate air bags, truck looks nice as it has snow plow kit in front and now lifted by springs in rear.
I hated how it sat with back lower. Dealer sent me to the shop and they do a ton of the new trucks as they sit goofy. Brett

 

There is a silent recall notice for rear block replacement through ford. I forget the exact wording but if you bring it to your dealers attention they will lift it for you at no cost.

 

TSB for the rear..

 

Here is the TSB : 13-3-8 MAR 13 Suspension - Rear End Sags Too Much With Light Loads

 

The Ford 350 blocks are even cheaper than the readylift kit. I did them on my 09 F250. IIRC, they and the new U bolts were about 125 plus shipping. I had no issue with vibration but I had (and still have) a super cab with a 1 piece driveshaft. I think the guys with the vibration are the two piece shaft guys who sometimes need to shim the carrier bearing. Another note, there are more than one set of 350 blocks. Each wheelbase has a different block with a different angle to retain the correct drive-train angle. Just order the ones for your exact truck except a 350.

 

I had the same issue with my 2012 f250. I put super springs in. Essentially, add a leaf. But their self adjusting and don't change the ride unloaded. I've had them in for 2 years no issues.