exhaust woes ......1973 340 into a 1965 barracuda

Still good. I use hi-temp rtv and stainless nuts, washers and conical lock washers.
I was told the gaskets will not hold up when using 273 manifolds on a 340/360 head but if there was never a problem then i will put 273 manifolds on my 360 build in my 65 barracuda