How to Install BBK Bolt-On Subframe Connectors w/ Seat Supports on your Mustang

IMPORTANT NOTE!!! Some Mustang Cobra models and convertibles require removal of one bracket on each sub frame connector to clear extra bracing used on these models. Once the bracket is removed these sub frame connectors will need to be welded in place.      

Step 1: Support vehicle on drive-on ramps, or by placing jack stands under rear axle and front control arms (this preloads the chassis correctly by putting normal pressure on the suspension).      

Step 2: Place connector over the front and rear sub frames, making sure the bar fits flat against the sub frame and con- tours to the floor pan with the slanted end plate towards the front of the vehicle. Be sure bars clear all brake, fuel and vacuum lines.      

Step 3: Tack weld bar (front and rear) to hold in place, and then finish welding all seams. Care must be taken when welding heavy-gauge connectors to thin-gauge sub frames, too high heat setting can “blow” holes in sub frames.      

Step 4: If you wish to bolt the connectors on, the exhaust system at the mufflers may have to be moved out of the way or completely removed for clearance of drill. Repeat steps 1 and 2.      

Step 5: Using a 3/8” bit, drill through both the connectors and the sub frame. Place bolt through hole before drilling nexthole (this keeps bar in position correctly and ensures an exact tight fit).      

Step 6: After all holes are drilled, install lock washer and nut to each bolt and tighten to 25-35 ft. lbs.      

Step 7: On models equipped with seat support brackets, simply install supplied lock nuts and flat washers to the existing seat studs protruding through the brackets. If a gap is present between the seat brackets and the floor pan, 1/2” flat washers may be used as a spacer to fill the gap.