Man you keep getting nothing but bad luck with that car. Maybe it wanted to be a gvr4 in it's past life(only a gvr4 owner would get that joke)

What rpm's are you getting the knock at?

Do you still have your 1g maf? if so put it in and see if it still makes the noise. If it sounds like a "mechanical" knock then most likely it has nothing to do with your maf at all.