nikon 180mm with long hood

Hi,

I know it's silly but...

I had Tamron 200-500, it has 86mm filter and big hood.

So far, I had nikon 180mm f/2.8 ED AF and built-in hood,
it was nice but 2 things problem: sunset, I can see little
flare (it has NO filter on it)
And during light rain I used rain cover lens/cmaera but
Hood had kind of nice fancy soft, I dont want wet on it.

So I looked and i bought step up ring from 72mm to 86mm
and I attach Tamron 200-300's big hood on nikon 180mm

Perfect! I see there is NO black shade all 4 edges!
All are full image.

Am I crazy?

KJR