This is for a 1999 V8 F-Body, 98 and up should all be similar. LT1 cars will also be similar but there will be some differences.
A nice clean flat surface will help, like a smooth concrete garage floor. The car needs to be way up on jackstands, four corners if you can. Front only, block the rear wheels real good. One good floor jack is needed, two would be helpful. This job can be done in one day but don't rush it. You'll want to do some other things while everything's apart like headers, motor mounts, starter, etc.
Disconnect the batteryís negative terminal.
Pulling the brakes and steering knuckles are pretty straightforward, no tricks needed.
If you're pulling the sway bar, it has a bracket on the drivers side which needs to come off first. Youíll access some of the fasteners in the forward wheel well after youíve removed two fender skirt bolts.
At least on my car, the motor mount bolts are poked in from the front with the nuts rearwards. Because of this, the alternator and A/C compressor need to be undone and moved out of the way to get the bolts out. The compressor is the most aggravating as to get to the compressor to bracket bolts, youíll need to remove the EGR stuff first. With the compressor out of the way, you then undo the bracket to block bolts to get it out. Itís this bracket thatís in the way of the motor mount boltís journey out of the mount. For the alternator, donít forget the one bolt in the rear at the top. Donít let the alternator hang on itís wires, the tiny exciter wire will snap like a potato chip.
Pulling the starter also makes accessing the motor mount bolt easier.
I see no reason why the motor mount bolts canít go in the other way around, rear to front with the nuts on the front. This simple change and youíll never have to move the alternator and A/C compressor to pull the motor mount bolts. You can bet I put them back this way.
Steering rackís next. Same issue as the motor mount bolts. The two bolts are poked down through the K-Frame with the nuts on the bottom. Youíll have to get these bolts out after youíve dropped the K-Frame away from the engine a few inches. Again, thereís no reason these bolts canít go the other way, poked up with the nuts on top. Yup, thatís how mine are now. You will not need to undo the power steering hoses or steering shaft to do the K-Frame swap.
I supported the engine with a blocked up jack stand under the crank pulley. The weight of the front of the car is balanced between two jackstands behind the firewall and the stand on the crank. Use some thin plywood or a rubber block to not damage the pulley grooves.
You can also support the engine from on top. Using a strut bar or shaft laid across the shock towers, run some ratchet straps to the exhaust.
Brake lines will need to come off the K-Frame. Donít forget one clip in the center at the steering rack.
If youíre gonna be undoing all the ball joints and everything, crack all the nuts and knock the joints through the steering knuckle now. This way, the car will hold it all for you rather than struggling with it out on the floor or workbench later.
If youíre pulling the upper control arms and springs out, youíll need to move the master cylinder. Undo itís nuts. Loosen the two side nuts on the ABS pump and wiggle it straight up. When loosened, you can move the master cylinder aside and the hard lines and ABS pump will move with it without bending up the lines.
Youíre now ready to drop the K-Frame. Undo the plugs on the rear of the frame that each sideís ABS cables connect to. Remove the front & rear bolts. Do the center bolts on each side last leaving them all out except for one or two threads. A good pry bar will be handy here. As you wiggle and jiggle, the frame will start to drop while leaving the engine behind. On the right side, the starter power and block negative cables will hang up on the frame so keep an eye on them. Tilt the frame using a 2 X 4 about three feet long to pry between the steering rack and the engine. Do this just enough to get those two bolts up and out. Now using your pry bar, pry the steering rack forward until both sides are clear of the frame. Pull the remaining chassis bolts. By now the K-Frame should be on itís way to the ground so stay out of itís way. A few extra hands will be very helpful here.
Aftermarket tubular K-Frames. Theyíre all made pretty much the same. The front four chassis bolts go through what started as tubing with heavy washers or plates welded on top and bottom. Everything else is welded to these components and presto, lightweight, stronger K-Frame with more clearance and access to other mechanicals. But wait, thereís a small problem with this setup. The welded, closed off tubes your chassis bolts go through will allow water in but not out. This trapped water will slowly rot away your critical chassis mounting bolts. Drill just one 7/32 or 15/64 hole at an angle on the rear side of the lower weld next to where the chassis bolt head will reside. This will allow any water that got in them to get out. I realize that I may be the only nut to do this...
Position the new frame in place. Youíll need to hang the frame from some wire to get the steering rack where it belongs. I found it very difficult to get the steering rack into the K-Frame just right. Once this is done, get the bolts in (poke the bolts up into the rack) and spin on some nuts but leave them loose.
I suggest you grease up the chassis bolts. This will make your wrenching torque work more towards clamping pressure, not overcoming thread friction. Start with the rear bolts. Wiggle everything around and youíll get everything lined up. Donít smack tight any bolts until youíve got them all started. Once theyíre all started, crank them in. Youíll need two long pry bars for the motor mounts, especially if youíve added poly motor mounts. Get the driverís side in first. Again, poke the bolts from the rear, not the front. Spin on a nut. Do the passenger side. Once you have both bolts poked and nutted, torque them down good. Re-check the chassis bolts. Now go back to the steering rack and finalize itís two bolts.
Re-install the starter, alternator and A/C compressor. If you over-tighten the A/C compressor bolts, you will crack the compressor and all your 134A will all come out. Re-install any other components you've removed. You'll need to take your time getting the brake lines and ABS wiring fastened to the frame. Tie-wraps work well but find high temperature rated ones. Otherwise, they'll turn brittle quickly and be gone. Safety wire, done correctly, can work well. Don't rush it.