Yes, your rebuttals are 100% bullshit. They're not informed or reasonable. You started with your answer and you're just making excuses trying to justify a terrible argument. Fiberglass is not a suitable repair for a structural sheet metal floorpan, there is no reasonable justification. There are cheap and easy options that work, fiberglass is not one of them. It's not "mopar police", it's auto 101.
My "alternative" with 18g and sheet metal screws
is a good one. It's an
actual solution with sound science behind it, not an "alternative" to a BS fiberglass "repair". It won't be pretty, but it will be 100% functional if done correctly. Fiberglassing a floorboard will not. That is not a "difference of opinion", if you think fiberglass is a viable solution then you have no business carrying out the repair. I don't care who you are or what your education is. Fiberglassing a floorboard is what flippers do to make something "look right" before they screw some poor bastard over that hasn't seen that trick before. It isn't structural, it isn't safe, and it will absolutely make things worse than they already are. I have seen the results of fiberglassing floor pans, it's not a viable solution.
The floor panels on these cars make up far more than 5% of the overall structural integrity. Hell, without subframe connectors the floor and rockers are all that hold the front and rear halves of the car together if we're talking about a convertible. Let's see your finite element model. Because I'm calling BS on your 5%. Take the floor out of your car and jack up the front end and let me know if the doors still open. You're just making it up as you go along. You gave terrible advice, and now you're bending over backward rather than admit you were wrong.
My degree is in Aerospace Engineering. I never took "roadbuilding" classes, and my focus was structural analysis. Not bridges, not roads, aircraft and aerospace structures.
Maybe I've offended your delicate sensibilities. But you know what? I started in a shop working in auto restoration almost 30 years ago. I've seen what happens when guys that have no clue what they're doing try to fix stuff they have neither the skills nor ability to fix. Maybe some of those guys had good intentions, but I've been the guy that had to clean up those mistakes on more than one occasion. So when I say that fiberglass is bullshit, and that the best way to go is a full panel replacement, it's because I've fixed the mess when morons fiberglassed floor pans, whether they did it with good intentions or not. I've made my own patches and stitched floors back together one piece of 18g sheet at a time. And after doing all of that, my recommendation is that if you're faced with a repair like the OP has the best course of action is to save up for the full panel, because in the long run not only is it
easier, but it's
CHEAPER too. And I know that because I've done it the other way.
You shouldn't need engineering classes to recognize that slapping some fiberglass down on a rusty floor panel isn't a real solution. It's not even a "temporary" solution, it's no solution at all.
This is the section that you're worried about, the rear part of the rear footwells and the transition to the rear seat area. It is a different section than the rest of the floor pan.
View attachment 1715505077
1974 DODGE DART Auto Metal Direct Floor Pan Footwells 410-1067-R
This is the other section that you'd really benefit from. Even using this pan I think you'll still need to make some 18g panels between it and the sections of your tunnel that you'll be able to weld to, but that would still be far easier than trying to fab some of the sections replicated here
View attachment 1715505079
1974 DODGE DART Auto Metal Direct Floor Pans 405-1067-R
I know it's a tough pill to swallow, but slowing down a bit and saving up for the panels is the better option compared to trying to make your own panels. If I had really considered the time and materials it would take me to do all the repair sections on my Challenger I'd have just waited and bought the entire floor, rather than patching and piece-mealing my way through. And it would have cost me an entire floor pan, an entire trunk pan, and half the damn cowl. Instead I made my own panels and cut down partial replacements. I spent less in panels, but with my time and the amount of welding I did, throwing in consumables like welding wire, gas and everything else I used to get it done I didn't come out ahead. I'd have been better off saving up for a couple months and buying the panels I needed.