I am a little concerned about taking too much metal off the car before I put some back on. This is a question about order of repair/replacement of the firewall

In terms of support currently I have:

2 jack stands at the front end of the torsion bar tubes
2 jack stands supporting a 2x2 steel bar running under the front floor pan just behind the wheel wells
2 jack stands supporting a 2x2 steel par bolted to the 4cyl engine mounts
2 jack stands supporting the tubes that stick out from the front of the rear trailing arms
Doors braced from upper rear seatbelt holes to welded plates where the speakers would be.
The longs are open but sleeved on the bottom and side with another layer of 18 ga from the door pillar to past where the long turns upwards.

Currently, after checking for the umpteenth time, the car is level, measures to factory specs accurately and the doors are on and the gaps are good (at least as they ever were)

In terms of lack of support currently I have:

The inner rockers (outer side of the longs) removed and some metal of the long cut back behind the jack point
A hole in the top of the passenger’s long to repair in the hellhole area
The inner lower firewall removed
6x6 hole in the rear corner of the passenger’s floor pan
Rust perforations along the side edge of the floor pan rear of the cross member
A 2x2 hole in the upper passenger’s firewall where it meets the top of the long

I need to replace the upper firewall—both sides—from the center of the “X” Stamp down to the flange where it meets the lower outer firewall. The center bulge is OK. I have a solid donor firewall.

I need to replace the lower outer firewall completely. I have the RD piece

Question: Is the car supported well enough to cut further, and what should I cut first?

I am thinking to be extra safe, I should drill the spot welds connecting the lower firewall to the upper firewall and replace rusted upper firewall sections one side at a time. Leaving the lower firewall in place for lower body lateral support.

Then once the upper firewall is solid, I cut the lower firewall from the longs and replace the lower outer firewall.

Am I over thinking this? Is it supported well enough to cut it all out at once? The top of the upper firewall/Targa bar combined with the support bar across the motor mounts should keep things laterally aligned enough to do it all at once shouldn't it?

Once again, thank you all for your advice, it is invaluable.

-Andrew

Pictures would really help

You've got a lot going on. I'd think about finishing the longs and closing them back up, then moving on. Getting into the firewall and floor you will be wanting to move those jackstands around, would be nice to have the strength back in it first.

What Perry said .................. Sounds like you have a lot going on.

What the others are saying.

I had removed a large part of my passenger side inner long, as well as the entire lower firewall, rear 1/2 of the floor and the jack receiver tubes and plates on both sides of the car.
The door gaps would change if I looked at them too hard.
But my project needed to be that far apart, based on what I wanted to do to it.

At the same time, my goal was to remove only what I absolutely had to to get the repair/mod done. Then I'd build the structure back and test all the gaps so if something had gone wrong, I'd know what it was and could adjust/correct before proceeding.

I believe that for any chassis work, it's better to have as much structure in the car as you can. I'd get strength back into the car before making it more noodle-y.

Keep up the great work!

Yeah I thought about this, but the stands are clear of everything for the firewall and every thing sits level—no movement of stands needed until I finish the longs and firewall

My reticence is because I am sandblasting in increments and I don't want to close the longs just yet—sand gets everywhere and it will be a pain to get it out of the longs if they are closed up

I still have some hell hole and long-through-the-firewall-stuff to do that would make things easier if I left them open. Maybe if I seal them up fully, tape over heater tubes, holes in the inner longs, seatbelt mounts etc, but sand always seems to get in somehow.

Thanks Chris, I hoped you would chime in, you are definitely contributing to the "button up the longs then move to the firewall" chorus.

Perry, sorry I would normally post picts but i am not near the car during the week
I'll get some up this weekend.

Thanks again

-Andrew

Looks like your getting all kinds of good input.

Heater tube ends. Spray paint can top and zip ties do the trick to keep out sand, walnuts and or glass.

Is it so rusted that sand blasting is needed? Bristle disc and Ospho will work wonders.

I normally do a light blast to get any loose stuff off, then ospho to get in any nooks and crannies, do the repair work then a light blast. Sometimes I do more blasting when I am getting off paint and glue.
I just ordered an eastwood thingy to try to cut down on the amount of blasting i need done. Its the rotary pneumatic removal tool
This thing:
Click to view attachment

I have about 200 hrs on mine.
Mines the TP Tools variant. I primarily use the med wire.

I assume 200 hours means that It works well

yep. I think I'm on my 4th or 5th wheel.
rust, undercoat and seam sealer.