CFMi - Standard Shackle Flip Kit for 1973–1991 Squarebody Chevy Trucks, K5 Blazers and GMC Jimmys

CFM Industries Standard Shackle Flip Kit

Upgrade your Squarebody rear suspension with this adjustable shackle flip kit designed for 1973–1987 (’91 R/V) Chevy and GMC trucks, K5 Blazers, and GMC Jimmys. This setup relocates the rear shackle position to improve suspension travel, articulation, and overall ride quality.

Compared to factory shackle placement, this system allows the suspension to move more freely while giving you the ability to fine-tune shackle angle and ride height based on your build.

Features and Benefits

• Adjustable rear shackle flip design
• Improves suspension travel and articulation
• Approximate 4-inch lift (varies by setup)
• Multiple shackle mounting positions
• 1-inch spaced adjustment holes
• Offset mounting holes allow 1/2-inch fine adjustments
• Welded nut strips for improved load distribution and easier installation
• Designed for custom suspension tuning

Fitment

Fits 1973–1987 (1991 R/V) Chevy and GMC Squarebody trucks, K5 Blazers, and GMC Jimmys.

What’s Included

• Shackle flip brackets
• Welded nut strips
• Mounting hardware

Optional Upgrades

• Heavy-duty custom-length shackles available
• Multiple shackle length options to match your suspension setup

Installation Details

• Requires removal of factory rear shackle hangers (rivets must be drilled or ground out)
• Bolt-in design using existing frame holes after hanger removal
• Gas tank removal recommended for easier installation (not required)
• Nut strips can be guided into frame using wire if tank is left in place
• Shackle position can be adjusted to suit spring length and desired angle

Performance Notes

• Lift height is approximately 4 inches with a stock-length shackle
• Actual lift varies based on shackle length, angle, spring rate, and bushing condition
• Best results achieved with proper shock length and healthy suspension components

Production

• Made to order
• Lead times typically range from 2 days to 2 weeks depending on shop workload

Why This Upgrade Works

This shackle flip kit is one of the most effective upgrades for improving ride quality and articulation on a Squarebody. It allows the suspension to work more naturally while giving you the ability to dial in geometry based on your specific setup.