Overview
The Pro Comp 58551 is a 5.5 inch rear lift block kit from Pro Comp Suspension for leaf spring vehicles. It contains two cast iron riser blocks plus four U-bolts, eight flat washers and eight hi-nuts for mounting them at the rear.
The taper keeps the driveshaft at a better angle once the rear is raised. Confirm your axle and spring pack fit before ordering this kit.
Key features
- 5.5 inch rear lift
- Tapered cast iron riser blocks
- Four U-bolts with heavy duty flat washers and hi-nuts
Clearance at a higher rear
Raising the rear adds height at the axle, which affects every part that runs between the axle and the frame. Brake hoses, the parking brake cable and bump stops should be checked for stretch or contact once the blocks are in place.
U-bolt length is also worth a look. Longer blocks change how far the U-bolts wrap around the axle, so confirm the thread engages fully on each nut before tightening. A thread that is too short will not hold the load safely.
Driveline clearance matters at larger lift heights. Watch the driveshaft at full droop and at full compression, and listen for vibration on the highway. Recheck the blocks and hardware after the first week of driving, since new hardware can settle.
- Brake hose length at full droop
- Bump stop contact at full compression
- U-bolt thread engagement on each nut
Specifications
| Brand | Pro Comp Suspension |
|---|---|
| Part number | 58551 |
| UPC | 614901112115 |
| Type | Rear block with U-bolt kit |
| Lift height | 5.5 in |
| Block material | Cast iron |
| Block shape | Tapered |
| Hardware | 4 U-bolts, 8 heavy duty flat washers, 8 hi-nuts |
Vehicle fitment
Confirm your leaf spring pack and axle position before ordering.
Confirm your vehicle’s year, model and trim before ordering.
Installation notes
A 5.5 inch lift raises the axle farther than smaller blocks, so check U-bolt length, brake line and driveline clearance after installation.
What’s included
Two cast iron riser blocks, four U-bolts, eight heavy duty flat washers and eight hi-nuts.
