Do i need to reinfrorce when cutting for fenderwell headers?????

When I put fenderwell headers on my car in the 1970's I tried several body shops trying to find somebody that would cut the inner fenders. None would do it, saying it would weaken the body. With the things I put my car through after cutting the holes for the headers I wouldn't worry at all about the structural integrity of the body for any normal type of driving. I launched my car through the air & landed pretty hard on more than one occasion (young and STUPID) & the body held up fine, though I don't know how. I didn't even have subframe connectors. I would think that if the front end was going to collapse because of those holes I gave it every chance to do so. :-D