has anyone here ever used 67 up exhaust manifold on 64 to 66 A body

I was writing I've had early A-Bodies forever and it was always a hassle with the exhaust. By the time you are done you are gonna want to shoot yourself (if you value your time). If you have a 273/318 the original ones will work fine even with a 4 barrel. You can find them cheap. If you are looking for performance the tti's are the best thing out there and the price is reasonable in 2019 money. You can cobble the exhaust real easy to save some $ to start off with. If you are planning future improvements this is a good place to start.