Sad that no one has made reproduction parts for this problem. My 72 sat for a good solid 18 years before I got it, and while I was tearing it down for cleanup and POR15 coating I discovered this problem. Its been leaking water in there so long that its rotted the floor near my passenger seat. I've done as Thumpin455 has suggested and replaced a good chunk of the metal. as for the "baffle" or "hat" as I've seen it called I made some out of large PVC pipe connectors cut down, coated in POR15 and then sealed in place and then re-coated the whole cowl again with POR15. hopefully it wont rust out again, if starts to leak or rust out again the whole panel will get patched off and blocked and retro fit a Vintage Air unit into it.

 

But that's no longer true. You are replying to a six-year-old thread. You can get the non-AC 71-73 cowl now. And virtually every other front-end sheetmetal part.

 

Yes this is true 2+2Gt, but again as others have mentioned we don't all have room in a nice shop to tare a car down that far. I mean I've got mine pretty well torn down as is but I can't keep it in my 1 car garage for lack of space and time. I have to store this car outside and replacing that cowl is not a 1 day job. I would love replace it fully and maybe someday I can go back and do it but for now the patch work will have to suffice do to constraints.

 

Depends on the patching. If it goes like a typical four-panel floor patch, it might take less time to replace the cowl than to put in three or four patches.