We have no way of knowing which quality of head or heads you will get if you buy these. If you are lucky (?) you will get a matched set of problems. Usually not. Usually the problems discovered with one head will not be the same problems discovered on the other. You can look forward to a possibility of the rocker arm stud holes and the studs not mounted in correct alignment so rocker arm geometry can be accomplished without expensive head repairs to fix the problem. The problem I just mentioned is far too common in the import heads. You may find valve seats that are soft or inferior. You may find that the deck thickness of one head is not the same as the other head and the valves between the two heads will not be at the same depth. The many different problems that keep showing up in some of the import heads give builders and never ending learning experience.
Or you could get a perfect pair.
Have you thought about how those flow numbers are gotten? A hint is the runner sizes are huge and are not shaped well at all. Sheeer mass size will give big flow numbers on a bench but will not perform as well as a well designed and smaller port.
They are not junk,because they are cheaper.
They are junk becuase they are junk and that is why they are cheaper is to try to sell a price instead of selling a cylinder head.
I like Canfield heads. I consider them to be among the best of the lower price range heads and will work pretty well for their cost with minor bowl work and minor tootsie roll finishing. Still you want to match the runner with the application when possible.
Ed