4 in blocks in a Dually

[GreenDually]

If I were to replace the 2.5 in blocks that are between the axle and the springs in my dually with 4 in blocks from a SRW truck what else would I need to change. Would shocks be long enough, would I have to shim the carrier bearing etc. I haul alot of heavy loads and would like the back of the truck to be a little higher.

[l.gerard]

Might want to change the shocks but the stock ones would probably work OK. Other than that you shouldn't need anything else.

[SmokeyWren]

Ford now has TSB 07-7-2 applicable to '05-'08 pickups. Note it's a lot more complicated than simply changing the spacer blocks.

Here is a severely edited list of the steps required. Refer to the actual TSB before you begin:

1. Remove U-bolts and nuts.
2. Place new spacer blocks on axle and raise axle to bottom of springs, seating springs in axle seat.
3. Install new rear axle U-bolts and nuts
4. Install new rear shock absorbers
5. Replace rear axle brake jounce hose assembly with new assembly. Bleed rear brake system.
6. Replace rear stabilizer bar links with new stabilizer bar links.
7. If necessary, install new (driveshaft) center bearing and/or shim assembly as required.
8. Check driveline angles
9. Adjust headlamp aim

[taken]

I have read that TSB as well. Most of the items in there are unnecessary. Brake hose is fine. Stab links are fine. Shocks are long enough. The only thing that needs changed is the blocks and u-bolts. Some guys have needed to shim the carrier bearing and some haven't. Can't tell you for sure if you will need to, but it's not hard to do if necessary.