Ya know, I didnt really look at it when I bought it because I didn't know that it was wrecked. It all seemed to fit fine...
Ahh managed to get a rise out of the master fabricator himself! Responses in red. And I understand the Devils Advocate approach. Someone has to do it!
I got ya! The frame rails look bent on every fox when the surrounding sheetmetal is taken away. If the car was wrecked in it's past,...and was consequently repaired by a reputable shop that had the ability to straighten the frame back to at least close to factory spec,..there'd be evidence of the remaining kink(s) where the frame was pulled on.
Coming from somebody that has built more than a few race cars not only for myself, but for quite a few others as well,...messing w/ any part of the box that you're gonna put 700-800 HP in is risky business,...especially when the by product of having that much power means that the whole mess will be traveling somewhere in the 150+ MPH range in a quarter mile.
As long as you put the structure back together (even using your round tubing, and brace it accordingly to at least rival the strength that the stock stuff had), then there'll be no trade off. But why take on all of the work to fabricate mount points for the front end, radiator, bumper, fenders when it's all there already done for you in brand new sheetmetal?
So now, Im off to a buddies house who has a fox in great shape with no motor in it. Going to take some measurements of his engine compartment and figure out what "square" really is so I can mimic that with my engine bay.
I'll bet you find no evidence of difference between your's and your buddies. At least not enough to go through all of the rebuilding you're getting ready to bite off.