I know it's been covered a million times, but maybe it will be helpful for someone about to to do their own to see some pics and specifics.
If you are not confident with your metalfab and welding, have someone else do it (like me :biggrin. Don't risk the structural integrity of your frame. If you have general fab skills and equipment, get after it.
Things I used off the top of my head.
BFH
7" grinder 24 grit open coat wheel (the floppy ones, not rigid ones)
4.5" grinder 24 grit
cutoff wheels
plasma cutter
profile guage
soap stone
masking tape
6 ton jack stands
floor jack
air hammer with blunt face hammer and chisels
chisels
cardboard
sharpies
scissors
clamp, vice grips etc.
welder, your cousins 110v ain't gonna cut it.
air nozzle
impact
Get the car in the air (at a comfortable height, hence big jack stands) and squared up.... Meaning put jackstands inthe same places side to side and don't do this sh!t in the dirt. Undo lower shocks and pull coilsprings. Brace the rear of the frame and install crossbrace before making first cut. I use an air hammer and blunt hammer bit to "massage" the wheel well edges in for room to work, and you need to anyway. You can see the dark area where I did this.
Have the wheel you intend to fit or at least one same diameter. Bolt it up and mark the frame where the tire is and add an inch for good measure, tire growth and future accomodations.
Break out the plasma (or a roll of cutoff wheels, torch, or whatever you want) and ROUGH IN your cut. Easier to remove it than put it back. I cut about up to the seam and finish it in from there.
Mount your tire and check for clearance. Don't forget to put your brake drum or disk back in place.
onna rub in the back here, but I need to straighten out that cut anyways, and make some room. Take into account the thickness of the filler plate. I used masking tape and eyeballing to mark where to cut for more clearance and straighten out the cut. I extended the cut on the outer half of the frame in the rear at an angle that matches the tire, why not.
Now take your cardboard and make your template for the plate. Use the dirty finger method and get it as right as you can.
Cut it out and knock the slag off it. Use a chisel, don't grind it. It's harder than chicken lips and breaks off easier. Grind it smooth and test fit it. Fits pretty good, but have to tune it up in a few areas where the white marks are.
Note: I fit it for a tight gapped corner weld.
Now, here's a step i think is important. The frame gets pretty thin by doing this. I'm no structural engineer, but I think adding ribs helps retain the strength if not improve it. No need to go crazy here, the less welding the better. I use 4. The two end caps are incorporated by extending them to the inside of the frame, and then the 2 ribs in the middle. Get a profile guage, and use it to mark the shape of the rib. Transfer it to cardboard and trim to fit, then transfer them to steel and cut them out.
Once you are happy with how they fit, wire wheel everything CLEAN, anywhere you are gonna weld. Inside and out.Grind the mill scale off the steel, inside and out until it's bare metal. Weld it in. I spaced and forgot to get pics of this. Still have to do the other side of anyone needs pics.
Using a cutoff wheel, mark exactly where these ribs are on outsided of the frame to see where they are when you cover them up.
Position your plate again. Mark where the ribs are with a straightedge and soapstone. I then use a plasma cutter and cut slots where the rib is, about the same thickness as the steel. I leave the cut attached at the end so I don't have to position 3 pieces.
Once everything is fitting right tack it in, where you have NICE TIGHT GAPS. You don't need much or any gap for a corner weld in 3/16 for good penetration, and the frame material is thin. So unless you want to be blowing through like crazy get it right. Recheck tire clearance before you finish weld. Weld. Take a BFH and close up the gaps as you weld. Weld slow, skip around, have something else to do while you allow cooldown periods.
If you are not confident with your metalfab and welding, have someone else do it (like me :biggrin. Don't risk the structural integrity of your frame. If you have general fab skills and equipment, get after it.
Things I used off the top of my head.
BFH
7" grinder 24 grit open coat wheel (the floppy ones, not rigid ones)
4.5" grinder 24 grit
cutoff wheels
plasma cutter
profile guage
soap stone
masking tape
6 ton jack stands
floor jack
air hammer with blunt face hammer and chisels
chisels
cardboard
sharpies
scissors
clamp, vice grips etc.
welder, your cousins 110v ain't gonna cut it.
air nozzle
impact
Get the car in the air (at a comfortable height, hence big jack stands) and squared up.... Meaning put jackstands inthe same places side to side and don't do this sh!t in the dirt. Undo lower shocks and pull coilsprings. Brace the rear of the frame and install crossbrace before making first cut. I use an air hammer and blunt hammer bit to "massage" the wheel well edges in for room to work, and you need to anyway. You can see the dark area where I did this.
Have the wheel you intend to fit or at least one same diameter. Bolt it up and mark the frame where the tire is and add an inch for good measure, tire growth and future accomodations.
Break out the plasma (or a roll of cutoff wheels, torch, or whatever you want) and ROUGH IN your cut. Easier to remove it than put it back. I cut about up to the seam and finish it in from there.
Mount your tire and check for clearance. Don't forget to put your brake drum or disk back in place.
onna rub in the back here, but I need to straighten out that cut anyways, and make some room. Take into account the thickness of the filler plate. I used masking tape and eyeballing to mark where to cut for more clearance and straighten out the cut. I extended the cut on the outer half of the frame in the rear at an angle that matches the tire, why not.
Now take your cardboard and make your template for the plate. Use the dirty finger method and get it as right as you can.
Cut it out and knock the slag off it. Use a chisel, don't grind it. It's harder than chicken lips and breaks off easier. Grind it smooth and test fit it. Fits pretty good, but have to tune it up in a few areas where the white marks are.
Note: I fit it for a tight gapped corner weld.
Now, here's a step i think is important. The frame gets pretty thin by doing this. I'm no structural engineer, but I think adding ribs helps retain the strength if not improve it. No need to go crazy here, the less welding the better. I use 4. The two end caps are incorporated by extending them to the inside of the frame, and then the 2 ribs in the middle. Get a profile guage, and use it to mark the shape of the rib. Transfer it to cardboard and trim to fit, then transfer them to steel and cut them out.
Once you are happy with how they fit, wire wheel everything CLEAN, anywhere you are gonna weld. Inside and out.Grind the mill scale off the steel, inside and out until it's bare metal. Weld it in. I spaced and forgot to get pics of this. Still have to do the other side of anyone needs pics.
Using a cutoff wheel, mark exactly where these ribs are on outsided of the frame to see where they are when you cover them up.
Position your plate again. Mark where the ribs are with a straightedge and soapstone. I then use a plasma cutter and cut slots where the rib is, about the same thickness as the steel. I leave the cut attached at the end so I don't have to position 3 pieces.
Once everything is fitting right tack it in, where you have NICE TIGHT GAPS. You don't need much or any gap for a corner weld in 3/16 for good penetration, and the frame material is thin. So unless you want to be blowing through like crazy get it right. Recheck tire clearance before you finish weld. Weld. Take a BFH and close up the gaps as you weld. Weld slow, skip around, have something else to do while you allow cooldown periods.