Exhaust Manifolds

I know that this has been discussed before but why do some people recommend the 360 truck manifolds for the A body small block when they won't fit. I think that it's been said that the right side fits but not the left and for that the 340 manifolds have been suggested but they are hard to find. What about manifolds from the volare / Aspen that had the 360 or a diplomat,etc. Was there a police interceptor 360?
IMHO you are always better to use the best manifolds for the car you have. There is a reason they were made specific for your car. Generally the older the better, exhaust manifolds got pretty ridiculous as time went on. You can buy ready to go exhaust and use factory tips and hangers. Otherwise you are reinventing the wheel all the time, and for what gain? All that time and finagling for a small gain, I just don't see the point. Or just spend the money and get custom.