Engine bay complete metal replacement

[rftroy]

I am working on a 68 Barracuda, but the architecture of the A and E body engine bays is very similar (and there are some really good restoration people here), so here is the deal.

My poor car was 'modified' many years ago by some people with less than stellar skills.  Originally a 383 car, they put a Hemi in it.  They did so by cutting the inner fenderwells all the way back to the firewall.  In the process, they also cut away part of the shock tower structures.  To make room for the headers, I was told a five pound sledge was taken to the firewall, and it was beaten into the engine compartment.  On the drivers side, the clutch pedal was bent inward toward the brake because the clutch wouldn't fully release with the deformed floor.

Here is what I plan to do:
I have a donor car and would like to remove the firewall, both inner fenderwells, and the radiator support, as an assembly.  The goal is to keep as many of the factory spot welds in place as possible.  From initial inspection, I plan to remove the upper control arm/shock support structure separately because it looks like it would be near impossible to access those welds with the inner fenders in place.
As a further challenge, I am thinking of trying to also remove the front floor pan without removing it from the firewall.  This may be precluded by clearance between the A pillars.

Has anyone done this before?  Any tips or warnings? 
The engine compartment structure removal seems feasible to me, but there may be pitfalls I haven't considered.
For entertainment, I have attached a picture of the damage.  This is my 68 383 Formula S convertible, so I feel it is worth whatever extra effort to keep as much factory appearance as possible.

Thanks,
Robert

edit:  P.S.  It just occurred to me that it would be near impossible to move the entire assembly, with floorpan, forward with the shock structure still attached.  RT

[RUNCHARGER]

Hmm: How is this car for rust? If it isn't rusty it might be easier to section pieces in with buttwelds rather than replacing entire sections? Hard to say without seeing the car in person.
Other than that yes, it might be worth rolling the front 1/3 of the car out the front and roll in a nice intact front 1/3 of the donor car in it's place. Do you have access to an industrial spot welder?

[rftroy]

No, can't spotweld.  Reconnections will need to be MIG.  Thus the desire to save good factory welds and appearance.
Bob

[jimynick]

If your aim here is to make this thing look factory, you've got a steep path to tread. The only reason I'd R&R the rad support would be in the interest of those spot welds and it's a Pyrrhic victory as you'll have lots of mig spots in other places, to do it. I'd take another 5lb hammer and gently work back the initial damages to the firewall to where the clutch works as it should and then hammer/dolly the rest. Buy new firewall brkts for the inner aprons, fit and mark them or put a couple of screws to hold the alignment and have a local body shop spot weld them together and then mig them with the replacement aprons back onto the firewall where damn few will ever see the mig spots. There's really not too much of a short cut to repalce all that tin and keep the factory spots, but then, that's just my    Good luck. 

[superdave]

@rftroy - I have nothing to contribute to the conversation but you have an impressive collection of Mopars!

[rftroy]

Yes.  And some of them even run!   

Bob